Smallpox

The general question of whether vaccines are effective might seem to have been settled long ago, but even today there are people opposed to vaccination who loudly claim that vaccination is ineffective, and that the modern pharmaceutical industry falsifies data to make it seems as if vaccination is effective. So let's look at the historical record from before that industry existed.

It seems that vaccination was controversial right from the start -- naturally so, since the very idea of injecting pus into one's child is enough to frighten the bejeebers out of anyone.

To separate emotional reactions to the very idea of vaccination from accurate data on the effectiveness of vaccination, let's look specifically at reports that include tallies of smallpox cases in which the vaccination status of the individual is known.

Death rate among vaccinated and unvaccinated smallpox cases, 1889-1897

The British government appointed a commission to study the practice of smallpox vaccination. Its final report, "A Report on Vaccination and its Results based on the evidence taken by the Royal Commission during the years 1889-1897" (scanned copies at Hathi Trust and archive.org) contains a detailed report both from the majority of the commission, and a dissenting minority. (Present-day opponents of vaccination would probably find the minority report interesting reading, but the minority report does not contradict the data summarized below.)

The data on fatality rate among vaccinated vs. unvaccinated cases of smallpox is found on pages 104-153:

"175. Specially valuable information bearing on the protective influence of vaccination is, we think, to be found in the careful and scientific investigations which have been instituted in the case of several recent local epidemics. The first of these was the work of Dr. Barry during the Sheffield epidemic of 1887-8. Five others have been appointed by medical men appointed by ourselves. Dr. Coupland reported on the epidemics in Dewsbury and Leicester, which took place in 1891-2 and 1892-3 respectively; Dr. Luff on outbreaks in London in 1892-3; Dr. Savill on an epidemic which visited Warrington in 1892-3; and Dr. Doupland on an epidemic in Gloucester in 1895-6....

202. We proceed now to consier the evidence derived from a comparison of the fatality of smallpox as it has affected the vaccinated and unvaccinated respectively. The most important information on this head is undoubtedly to be found in the reports ... to which we have already referred. Great pains were taken to ascertain the condition as to vaccination of the persons attacked... "

Their findings with respect to fatality were summarized by a table on page 227 of "The Elements of Vital Statistics", 1899:

SheffieldLondonDewsburyWarringtonLeicesterGloucester
Vaccinated cases under 10353 110 44 33 2 26
Fatality per cent 1.7 0.0 2.2 6.0 0.0 3.8
Unvaccinated cases under 10288 228 174 32 107 680
Fatality per cent 43.926.732.167.514.041.0
Vaccinated cases over 10 37741643577 4601971185
Fatality per cent 5.1 2.32.6 6.41.010.0
Unvaccinated cases over 10 322 181 192 36 51 88
Fatality per cent 54.220.918.733.37.839.7

From this table it seems clear that vaccination reduced the fatality among smallpox victims by a factor of four or higher; among those under ten years of age, it reduced fatality by a factor of 25 or higher.

A frequently-cited article taking issue with this conclusion is in the book "The Wonderful Century" by Alfred Wallace, a well-respected scientist. (Two earlier chapters in the book, The Neglect of Phrenology and The Opposition to Hypnotism and Psychical Research) call his scientific judgement into question, but that's another story.)

The chapter on smallpox vaccination was originally published as a separate pamphlet: Vaccination a Delusion, its Penal Enforcement a Crime:

" This Essay has been written for the purpose of influencing Parliament, and securing the speedy abolition of the unjust, cruel, and pernicious Vaccination laws. For this purpose it has been necessary to speak plainly of the ignorance and incompetence displayed by the Royal Commission, proofs of which I give from their "Final Report" and the evidence they have collected and printed...

I thus abundantly prove, first, that in all previous legislation they have been misled by facts and figures that are untrue and by promises that have been all unfulfilled; and that similar misstatements have characterised the whole official advocacy of Vaccination from the time of Jenner down to this day. I claim, therefore, that all official statements as to Vaccination are untrustworthy. ...

I then show that all the statistics of small-pox mortality, whether of London; of England, Scotland, and Ireland; of the best vaccinated Continental States; of unvaccinated Leicester; or of the revaccinated Army and Navy, without any exception, prove the absolute inutility of Vaccination; and I feel confident that every unprejudiced person who will carefully read these few pages, and will verify such of my statements as seem to them most incredible, will be compelled to come to the same conclusion. ...

But before proceeding to discuss the statistical evidence set forth in the reports of the Commission, I have again the disagreeable task of showing that a very large portion of it, on which the Commissioners mainly rely to justify their conclusions, is altogether untrustworthy, and must therefore be rejected whenever it is opposed to the results of the great body of more accurate statistical evidence. I allude of course to the question of the comparative small-pox mortality of the VACCINATED and the UNVACCINATED. The first point to be noticed is that existing official evidence of the greatest value has never been made use of for the purposes of registration...

Yet every vaccination is officially recorded--since 1873 private as well as public vaccinations--and it would not have been difficult to trace almost every small-pox patient to his place of birth and get the official record of his vaccination if it exists. As the medical advisers of the Government have not done this, and give us instead partial and local statistics, usually under no official sanction and often demonstrably incorrect, every rule of evidence and every dictate of common sense entitle us to reject the fragmentary and unverified statements which they put before us ... [examples of several people being mistakenly listed as unvaccinated] "

It seems his objections to the data boil down to

To the first point, only three of the six cities have death rates much higher than 18 per cent, and omitting them does not change the results. To the second point, let the Royal Commission's final report speak for itself:

" 205. The facts recorded by Dr. Barry have been subjected to a severe scrutiny by the opponents of vaccination, but they have not, in our opinion, been materially displaced. It has been shown that three or four of those attacked have been included in the class of unvaccinated who ought to have been placed in the vaccinated class, but, on the other hand, it is probably, as Dr. Barry suggests, that of the doubtful cases which have been included amongst the vaccinated, quite as many ought to have been transferred from the vaccinated to the vaccinate class. Many were put in the vaccinated class of whose vaccination there was very meagre evidence. Some, no doubt, may have been vaccinated after the date of the census, in which they were enumerated as unvaccinated. Making full allowance for this, we do not think it would modify the conclusion that the fatality was much higher amongst the unvaccinated than the vaccinated. It is obvious that a considerable transfer might be made from the one class to the other without altering the result in this respect. "

Another book cited by vaccination opponents, "Leicester: Sanitation versus Vaccination", by J.T. Biggs, 1912, is chock-full of figures, but seems to have no statistics comparing mortality among vaccinated and unvaccinated cases, and so says nothing about the efficacy of the vaccine in reducing mortality among those who do catch smallpox.

Incidentally, W. T. Sedgwick's (impromptu?) 1902 speech, "Remarks on Opposition to Vaccination" discusses Wallace's remarks in passing, and antivaccinationist sentiment in general. Reading it makes you think that not much has changed in 110 years!

Death rate among vaccinated and unvaccinated smallpox cases, 1900-1925

I searched Google Scholar for freely available papers between 1900 and 1925 with keywords smallpox, efficacy, and vaccination and which had sufficient information to estimate mortality in smallpox cases with and without vaccination.

Of the first twenty search results, only three met the above criteria:

1913: "Studies in small-pox and vaccination", by William Hanna, M.D.

(Full text and gruesome pictures at hathitrust.org, Google Books, OCR text at archive.org)

This study said in part

" The series of small-pox cases under consideration has been collected from amongst those which have been admitted to the hospitals of the City and Port of Liverpool during the past ten years. The large majority occurred during the above-mentioned epidemic period (1902-3)...

Part I - A Statistical Study of 1,163 Cases of Small-Pox, with Special Reference to Vaccination in Modifying the Disease.

... The cases of small-pox numbered 1,163, consisting of 943 vaccinated in infancy and 220 unvaccinated. ... amongst the 943 cases which were vaccinated in infancy, there were twenty-eight deaths, or 2.9 per cent, and amongst the 220 unvaccinated cases there were sixty deaths, or 27.2 per cent; that is, the ratio of deaths to attacks is ten times as great in the unvaccinated as in the vaccinated. ...

An examination of the deaths recorded amongst the vaccinated under each age-group reveals the interesting fact that no death occurred until the 20-30 year group is reached, and the case-mortality for this group is only 0.9 per cent. It will be observed, however, that the percentage case-mortality amongst the vaccinated steadily rises from this point onwards in life, but never exceeds 10 per cent.

On contrasting these figures with those amongst the unvaccinated, we observe a striking difference. Under 2 years of age the deaths are 58 per cent of the cases attacked, for 2-5 years 30.6 per cent, and the figure then falls until 10-15 years, when it is 3.2 per cent.

This decrease may be attributed to the gradual development of the natural resistance and recuperative power of youth enabling the patient to recover from the disease; this may be compared with what is observed in other infectious diseases. From adolescence onwards the mortality in the unvaccinated gradually increases, until it reaches 50 per cent at the periods from 40 years and upwards. "

1923: "Small-Pox and Vaccination in the Phillipines", by John McVail, M.D.

This review of the 1918-1919 epidemic in the Phillipines said in part
" In the 1919 Report (p. 193) it is stated, regarding the epidemic up to that time, that of 56,018 reported cases, 52,763, or 94 per cent, had never been vaccinated. ... Drs. Heiser and Leach, in the paper already referred to, give various particulars regarding the prevalence of smallpox in Manila, where the disease could be kept under skilled observation. Of 1,326 cases in 1918, only 177 occurred anmong the successfully vaccinated, and of 989 deaths only 60, or 7 per cent, were in that class. "
(See also: Annual reports of the Philippine Health Service)

1924: "The Epidemic of Virulent Smallpox in Windsor", F. Adams

This report says in part
" The total figures for the whole epidemic covering the Border Cities, Amherstburg, Maidstone and Detroit are as follows:
CasesDeathsMortality
Never successfully vaccinated453271%
Vaccinated successfully 12 to 65 years before1000
Vaccinated successfully in incubation period i.e. came down ill with smallpox and taking vaccination1200
You will note that no person who had ever been vaccinated successfully at any time in his or her life, whether it was in the incubation period of smallpox or years and years before, died of smallpox. You will note also that of the persons who had never been successfully vaccinated and who developed smallpox seventy-one percent died of the disease. That is a wonderful story in regard to the efficacy of vaccination as mitigating the severity of the disease, but the figures by no means tell the whole story.

A few persons who had never been successfully vaccinated recovered but they all had severe attacks and had a terrible fight for their lives.

On the other hand persons who had been previously vaccinated successfully, no matter how long before, had mild attacks. Incidentally it should be mentioned that no one vaccinated successfully within twelve years took smallpox at all. "

Summary

The three papers report measurements of mortality among cases of smallpox as follows:

Liverpool 1903 : vaccinated, 3%;  unvaccinated, 27%
Manila,   1918 : vaccinated, 37%, unvaccinated, 80%
Windsor,  1924 : vaccinated, 0%;  unvaccinated, 71%
So it does seem that these three papers support the notion that cowpox vaccination was effective at reducing incidence and mortality of smallpox.

In my quick search, I didn't see any paper which reported that vaccination was generally ineffective; the Philippines paper detailed many difficulties in vaccination (e.g. lack of cooperation, lack of followup to make sure the vaccination took, and vaccine spoiling), but even with those difficulties, mortality was cut in half by vaccination.

Other Data

1805 English Report

"The Evidence at Large, as Laid Before the Committee of the House of Commons, Respecting Dr. Jenner's Discovery of Vaccine Inoculation: Together with the Debate which Followed : and Some Observations on the Contravening Evidence, Etc", by George Jenner, contains testimony from scores of witnesses, mostly doctors, about their experience with vaccination.

1857 English Report

The "Blue Book" of 1857 on vaccination, "Papers Relating to the History and Practice of Vaccination: Presented to Both Houses of Parliament by Command of Her Majesty by Sir John Simon, General Board of Health, contains a wealth of statistical data from many countries, as well as a historical account of vaccination and the anti-vaccination movement.

For instance, on page 187, it says

"Wirtemberg

The following statement, abridged from official documents, relates to the only important small-pox epidemic (1848-1850) that has taken place in our country since the introduction of vaccination, and illustrates in figures the influence of vaccination upon the course and mortality of small-pox:
VarioloidVar. VeraDied
Not inoculated24.4%76.6%39%
Unsuccessfully inoculated28.2%71.8%36.9%
Successfully inoculated93.0%7.0%3.6%
Successfully vaccinated91.0%8.9%1.7%
"

1871, London

In the appendix to the "Thirty-fourth annual report of the registrar-general" a "Letter to the registrar-general on the causes of death in England in 1871", by William Farr, Esq., M.D., F.R.S." said
" This year is memorable for an epidemic of small-pox, which ravaged several parts of the kingdom in a way of which there has been no example since the year 1838, when the deaths by small-pox were 16,268... [in the year 1871] the deaths by this single disease ran up to 23,126...

the Managers of the Metropolitan Asylum District at the close of the 1870-1-2 epidemic appointed a Committee... "to report upon the returns obtained from the several hospitals of the Managers, with regard to the cases of small-pox treated therein"...

The Committe shows that 14,808 patients were treated in the hospitals, where 2763 of them died. The mortality was at the rate of 19 per cent on the cases treated.... 11,174 cases occurred in persons vaccinated, 3634 in persons unvaccinated...

Upon one point there can be no doubt. Cases of small-pox in persons unvaccinated... are excessively fatal; 1628 in 3634, that is 45 in 100 such cases end in death.

The vaccinated here again enjoy a relative immunity; yet even of them 1135 cases in 11,174, or 10 in 100 terminated fatally. "

The paper "The Smallpox Pandemic of 1870-1874", by J.D.Rolleston, 1933, said
" the deaths of the unvaccinated in the London hospitals were 45%, which was double the mortality in private practice. Moreover, in vaccinated persons suffering from smallpox the mortality in hospitals was 10% as compared with 3% in cases treated in their own homes. "
Evidently the people in hospital were worse off than those at home, but among those treated in hospital, we have these statistics:
London hospitals, 1871 : vaccinated, 10%;  unvaccinated, 45%

1871, Prussia

" Zeitschrift des Preussischen Statistischen Bureaus, Volume 13", page 155, says that in Cologne, out of 11 districts, the number of districts with death rates in the following ranges among smallpox cases was as follows:
        unvaccinated   vaccinated
under 10%    1             2
10%-30%      2             8
30%-50%      0             0
50%-70%      2             0
70%-100%     4             0
not reported 2             1
To summarize this odd way of reporting statistics: among smallpox cases in Cologne, the death rate was 10%-30% for vaccinated patients and usually higher (in 4 districts, 70% or higher) for unvaccinated patients.

That is just one slice of a large table which gave that information for 35 counties. It summed up the results for all counties as follows:

        unvaccinated   vaccinated
under 10%    15            87
10%-30%      70            350
30%-50%      114           17
50%-70%      103           0
70%-100%     87            0
not reported 139           74
At this larger scale, it appears that the most common reported death rate among unvaccinated smallpox victims was 30%-50%, but for vaccinated smallpox victims it was 10%-30%. The text under the table says
" ... it seems certain that mortality among the unvaccinated was 3 or more times worse than among the vaccinated... "

1901, Boston

"The Last Smallpox Epidemic in Boston and the Vaccination Controversy, 1901-1903", 2001, said in part
" From 1901 to 1903, there were 1596 cases of smallpox, with 270 deaths, in a city with a population of approximately 560,900. The attack rate was 3 cases per 1000 persons, with a case fatality rate of 17 percent. "
That paper refers to a primary source, "A Review of 700 Cases of Small-Pox", by Irving Bancroft, MD, 1907, which said in part
" The following cases occurred under the writer's observation while he was the resident physician of the Board of Health Hospital in Boston during the epidemic of 1901-2. The epidemic consisted of about 1600 cases and this group is of those which occurred during the middle of the epidemic. The figures are from the original notes taken on cards at the bedside by the writer...

Table No. 2
Showing severity of small pox in relation to vaccinated and Unvaccinated persons
FatalSevereModerateLight
Unvaccinated
(No scar visible)
26%42%15%17%
Unvaccinated
(Vaccination attempted. No scar visible)
25%40%12%23%
Vaccinated
(In childhood. Good scar)
8%13%14%65%
Vaccinated
(Child. Scar not of the typical variety, i.e. not pitted)
14%23%11%52%
Vaccinia and vaccinated once before.0%25%8%67%
Vaccinia and never vaccinated before.7%20%7%66%
The above table... shows markedly the effect of vaccination and seems to confirm the opinion that a fatal case of Variola does not occur after a recent successful vaccination. On analysis of the cases which were undoubtedly vaccinated and which died, it is found that the youngest was 28 years old and average was 47, so that it is fair to assume that vaccination prevented death for many years... "

Related Pages

Historical note: 1914: "Early Vaccination Controversy With an Original Letter by Jenner", by Phillip Brown, M.D.

A fourth article, while lacking enough information to estimate efficacy, reminds us that, before vaccination with cow-pox, people were vaccinated with actual smallpox:
" For one hundred years inoculation had been in practice as a preventive to small-pox, that is, the disease itself was transferred from case to case, it being recognized that an immunity followed recovery, and the mortality from cases so inoculated was slight as compared to that which obtained from the disease itself, called the "natural small-pox" to distinguish it from the inoculated. "
It also reminds us that anti-vaccination controversy has been with us since the beginning:
" The first public opposition that was made to Jenner's report of his discovery, was in a publication of Dr. Moseley's in 1798. ... Following Moseley's attack, reprinted two or three times, the opposition grew quite violent. Charges of murder and falsehood were interchanged among the disputants without the smallest ceremony; the medical journals foamed with the violence of their contention; it raged in hospitals and sick chambers; and polluted, with its malignity the sanctity of the pulpit, and the harmony of convivial philanthropy. "