Variants and vaccines – CounterPunch.org

At the end of 2020, the British noticed that coronavirus cases were skyrocketing in the Kent region. The culprit turned out to be a variant of the COVID-19 virus identified in September. Mutations in the genetic makeup, RNA, lead to variants. They are still COVID-19 viruses, but they may behave differently. The variant first identified in Kent, UK (scientific name B.1.1.7, WHO name Alpha) is more contagious than the original strain that emerged from Wuhan, China.

The number of other people each infected person infects is called the basic reproduction number, or R0 (“R zero”), in epidemiological jargon. It is a measure of the biological characteristics of an infectious agent, but it can be affected by social and environmental conditions and human behavior (eg, crowding vs social distancing, ventilation, face masks). The R0 for seasonal influenza is 1.3. The R0 of measles is around 15. As found in Wuhan, the R0 of the original COVID-19 strain was 2.4-2.6. The R0 of the Alpha variant is 4 to 5.

The beta variant (scientific name B.1.351) appeared in South Africa in October 2020. The AstraZeneca vaccine was found to be ineffective against the beta strain, resulting in its use being paused there in February 2021. (The AstraZeneca vaccine may make a comeback in South Africa, as it is effective against the Delta strain, which is on the way to becoming dominant there.)

The Gamma variant (scientific name P.1) appeared in Brazil in December 2020. Manaus, in the Amazon, had experienced a severe outbreak of COVID-19 in 2020, so it was estimated that 50% of its residents had been infected. by October 2020. In December, Manaus experienced a second wave, more severe than the first, in which the Gamma strain was detected. It should be noted that Gamma has caused infections in people who had previously been infected – demonstrating that infection with one strain of COVID-19 might not lead to immunity against a different strain.

The Delta variant (scientific name B.1.617.2) was responsible for the second wave from April-June 2021 in India. At its peak, India had nearly 400,000 cases and over 4,000 deaths per day, which would be a serious undercount. True cases may have exceeded one million per day, and true deaths may have been 10 to 15,000 per day. Between January and June 2021, an additional 3-4.7 million deaths occurred in India. The Delta variant has an R0 of 5 to 8. Each case of Delta leads to 5 to 8 additional cases. An infected person is likely to infect everyone in the household. This gives it an evolutionary advantage over even the Alpha variant. The WHO declared Delta a “variant of concern” on May 10. As of mid-July, Delta was the dominant variant in the United States.

A study of 4,272 cases of Delta from Public Health England (published July 21 in the New England Journal of Medicine) concluded that two doses of Pfizer-BioNTech vaccine were 88% effective and two doses of AstraZeneca vaccine were effective at 67% in preventing symptomatic COVID-19. (One dose of Pfizer was only 35.6% effective against Delta.) In contrast, according to Israeli data from mid-June to mid-July 2021, the Pfizer vaccine was only 39% effective for prevent infection with COVID-19, but these data have not been published in the peer-reviewed literature. It should be noted, however, that the vaccination was 91.4% effective in preventing severe COVID-19. On July 22, Los Angeles County Public Health Director Barbara Ferrer announced that 20% of COVID-19 cases in LA County over the past month were breakthrough infections in people who had been fully vaccinated.

Regions of the world that have vaccinated their populations with China’s Sinopharm and Sinovac vaccines are experiencing epidemics. Indonesia, which is currently experiencing a major Delta wave, has relied on vaccines from China.

While the currently available mRNA vaccines (Pfizer and Moderna) are not as effective against Delta as they are against the original COVID-19 virus, they nevertheless prevent hospitalization and death. Currently, in the United States, 97% of people hospitalized with coronavirus and 99.5% of those who die from coronavirus are not vaccinated. Obviously, we must continue to promote immunization.

Delta, however, put “collective immunity” almost out of reach. The percentage of the population that needs to be immunized [whether from vaccine immunity or from infection with the original virus (I hesitate to say “wild type”) or a prior variant] to obtain collective immunity is derived from R0. Based on the estimate that the original COVID-19 strain had an R0 = 2.5, the

% necessary to achieve collective immunity = 1 – 1 / R0 = 1 – 0.4 = 60%

which is close (albeit a little less than) 70%. It is on this basis that government officials tell us that we need to immunize 70% of the population. Since Delta’s R0 is estimated between 5 and 8, using R0 = 6,

% necessary to achieve collective immunity = 1 – 1 / R0 = 1 – 0.17 = 83%

The next worrisome variant (or the one after, or the one after… twenty remaining letters of the Greek alphabet) may not just be as contagious as Delta. It can also escape vaccine immunity (like beta with AstraZeneca) or natural immunity (like gamma) more easily. It is quite plausible that vaccines will need to be reformulated to match future variants.

As difficult as it may be to achieve, we must continue to strive for collective immunity. In the United States, FDA approval will allow employers and schools to mandate vaccines. During the current Delta Wave, due to groundbreaking infections, even those vaccinated would have to maintain social distancing and wear masks indoors. With companies pressuring government officials not to impose a lockdown, it will be up to the informed to take action on their own.

The current Delta wave will also pass. Many will die, but because many old and infirm people were vaccinated, not as many as during the dark days of January. Since the onset of COVID-19, the epidemic curves of the United States and the United Kingdom have been shaped similarly. Of course, the United States has five times the population of the United Kingdom (331.4 million versus 68.2 million), so its absolute number of cases is generally around five times that of the United Kingdom – except since late. June, when Delta, which hit the UK earlier, gave the UK a higher absolute number of daily cases than the US During the Delta Wave, daily cases in the UK approached those of its worst days in early January. However, the UK Delta wave appears to have peaked. The Delta wave of the United States is still in its exponential rise.

Regardless of what the future may bring, the task ahead is to deliver life-saving vaccines to the world. To prevent more Indian-style disasters around the world, we need to support an accelerating global Covid vaccination campaign. The Biden administration’s decision to support the suspension of intellectual property rights for vaccine manufacturing was a step in the right direction. On June 9, the United States announced that it would purchase and donate 500 million doses of the Pfizer vaccine. This is clearly insufficient when less than 5 doses per 100 people have been administered in Africa (total population 1.34 billion). American taxpayers have subsidized the development of mRNA vaccines. It is a travesty that Pharma benefits so generously from public investment. Vaccines that save lives are public goods that belong to the people.