The origin of the 1977 Russian flu is a political mystery

2024 Author: Seth Attwood | [email protected]. Last modified: 2023-12-16 15:55

In November 1977, the world's attention was captured by another influenza pandemic. Soviet doctors were the first to report it, so in the West the strain was immediately dubbed "Russian" and even "red" flu. And soon it was noticed that the virus infects almost exclusively youth of draft age. And although the symptoms of the disease were very mild, the press immediately started talking about the malicious spread of the disease, aimed at undermining the defenses of the NATO bloc.

Indeed, influenza A / USSR / 90/77, like the current coronavirus, especially actively affected close groups, including barracks. Reports of outbreaks at some military bases and universities described them as "explosive". In January 1978, the infection spread to personnel at Upper Hayford Air Force Base. More than 3,200 cadets have become infected at the United States Air Force Academy (USAFA) in Colorado, for which training had to be suspended.

It was at this time that the peak of activity of the famous Soviet NGO "Biopreparat", under the auspices of which top-secret institutes and laboratories were developing biological weapons, fell. In the first half of the 1970s, specialized factories for the production of such combat agents were launched in Omutninsk, Stepnogorsk and Berdsk. And although the flu was never the main object of interest of military microbiologists, the same enterprises were engaged in its study, and vaccines were often produced here.

A genetic analysis of A / USSR / 90/77 added fuel to the fire, which revealed large differences in its RNA from other strains circulating at that time. But the virus showed almost complete coincidence with the FW 1950 strain, isolated in the early 1950s. "It is likely that the H1N1 influenza virus remained frozen in nature or elsewhere, and was only recently introduced to humans," the study authors concluded. This clause - "anywhere else" - for a long time ruined the reputation of the "Russian flu".

Scariest serotype

To begin with, recall that the surface of influenza virus particles contains characteristic proteins - hemagglutinin (HA) and neuraminidase (NA). According to the forms of these proteins, influenza strains are divided into serotypes. Today, there are 18 known HA subtypes, three of which carry strains that infect humans - H1, H2 and H3. 11 subtypes of NA are also known, including the epidemically dangerous N1 and N2 variants for humans. Well, the most formidable is the combination of H1N1 - it was this serotype that caused the Spanish flu pandemic in 1918 and the swine flu pandemic in 2009, as well as about a dozen outbreaks of a smaller scale.

It also includes the "Russian" strain A / USSR / 90/77, although several previous large-scale pandemics were caused by influenza H2N2 (in 1957) and H3N2 (in 1968). This is why geneticists compared it to earlier H1N1 strains that spread between 1947 and 1956, finding that their RNA differs in only eight regions. For comparison, it differed from other H1N1 strains circulating in 1977-1978 in 38 positions.

It is with this that the unusual feature of the pandemic is connected, which affected almost only young people under the age of 23-26 years. The older generation, who encountered the same virus around 1950, already had immunity from it. But this feature also led to questions about the origin of the strain. Modern concepts of the evolution of viruses do not allow us to think that it could have survived in the population for about a quarter of a century, infect and at the same time practically did not change (this process is called "antigen drift"). Where did he come from?

Non-Russian flu

Subsequent studies have shown that the name "Russian" flu was in vain, although the epithet "red" would fit quite well. Although Soviet doctors were the first to report the strain, even before them, in May 1977 the same strain was isolated in northeastern China, in the provinces of Liaoning and Jilin, as well as in the metropolis of Tianjin. In addition, new technologies for sequencing nucleic acids, which appeared later than 1977, made it possible to more closely study the RNA of the virus.

The previous conclusions were generally confirmed. The "red" influenza A / USSR / 90/77 was indeed very close to some old strains: with the viruses isolated in Rome in 1949 and in Albany in 1948-1950s, it coincided by 98.4 percent. At the same time, the danger of the disease turned out to be really small. The probability of death was less than five per 100 thousand cases - lower than the average for seasonal flu (six per 100 thousand). All this could not fail to lead scientists to another idea about the source of the sudden pandemic.

The fact is that at the end of the 1970s, around the world, there was a development of "live" vaccines containing attenuated (attenuated) particles of the virus. Such live attenuated influenza vaccines (LAIV) began to appear in the 1950s: they do not require cold storage and can be introduced into the body intranasally. According to available data, by the early 1970s, several LAIV tests had passed in the USSR, covering tens of thousands of people. Similar studies were conducted in China, in particular at the Beijing National Vaccines and Vaccines Institute (NVSI).

Vaccine version

Their authors probably faced the problem of "recovery" of a weakened strain, which, while rapidly changing, regained its usual virulence. In the early stages of LAIV development, it was quite acute. One of the ways to prevent such a scenario is to give the strain a temperature sensitivity, due to which it quickly dies in an infected organism. It often serves as an important marker for identifying an attenuated strain. This sensitivity was also demonstrated by A / USSR / 90/77, and it was more pronounced in him than in the strains of the 1950s. All this may indicate that the virus has undergone artificial manipulation.

Indirectly, the very time of the unfortunate event speaks of this. In 1976, an unexpected outbreak of H1N1 influenza broke out at the US base at Fort Dix. And although it was then quickly localized, and the epidemic did not happen, the case attracted a lot of public and political attention. President Gerald Ford promised an early development of a new drug and a universal vaccination of Americans against the new flu. Both the outbreak and the American program (although it was never implemented) attracted the attention of specialists around the world. So it's not impossible to use older H1N1 strains to get a vaccine.

Even the former head of the Chinese Academy of Medical Sciences, who once mentioned that "the appearance of the 1977 virus was the result of trials of a vaccine for the H1N1 virus, which were carried out in the Far East with the involvement of several thousand military volunteers," even blurted out about the real source of the pandemic. Note that in 1978, after consultations with the official representatives of the USSR and the PRC, the WHO leadership abandoned the version with the laboratory incident. But this is apparently a political question.

Political hesitation

Several years ago, the American Society for Microbiology mBio published an extensive review on the mystery of the "Russian" flu. It ends with instructive statistics: scientists have collected several hundred materials on this topic, published in English between 1977 and 2015. - both in the academic press and in the media of a wide profile, - and considered the versions of the origin of the ill-fated strain, which are mentioned by their authors.

It turned out that if we compare the frequency of occurrence of this or that version - "natural" or "laboratory" - then it correlates well with the political realities of the time. For example, in the late 1980s, when relations between the USSR and Western countries were very warm, there were more frequent explanations that the virus remained frozen in nature. And since the late 2000s, when the political situation changed, versions of artificial origin began to dominate.

However, the final and correct answer is still unknown. There is no unequivocal evidence of a laboratory incident - and the origin of the 1977 "Russian" flu is still a mystery.