How to test the effectiveness of one vaccine against new strains
This can be done in a laboratory setting
But Israel provided an opportunity in the regimeconduct such an experiment with the Pfizer vaccine in real time without any equipment. The fact is that the country was one of the first to receive Pfizer and quickly vaccinated the majority of its 9.3 million inhabitants. So far, 78% of Israelis over 12 years of age have received both doses) and began publishing detailed data.
As a result, the number of infections dropped sharply, in May-June there were days when no one died from COVID-19, the Israelis returned to normal life.
However, a senior health official warned last week that the new Delta strain could force Israel to reintroduce lockdown.
If it reaches Israel, then we will get to the quarantine that we so desperately want to avoid.
Asher Shalmon, Doctor and Director of the Department of International Relations of the Ministry of Health
Just two days later, the ministry announced that inIsrael has had 10 cases of the delta strain, eight among people who recently returned from abroad, and two who appear to have contracted the infection in the country.
7000-8000 new ones are being identified in Israel nowcarriers of the virus every day, the country manages to conduct genetic studies not of all new cases, but only a statistical sample, which does not allow health authorities to fully control the options.
How effective are mRNA vaccines
mRNA vaccines, also called "geneticvaccines ”is the result of an innovative biotechnological approach that turns body cells into molecular factories for the production of proteins that activate a pathogen-specific immune response
US Centers for Disease Control and Preventionalso published three studies on the effectiveness of mRNA vaccines Pfizer/BioNTech, Moderna and vector Janssen/Johnson & Johnson. The New York Times writes about them.
In one study, researchers observed thosewho live in nursing homes and are vaccinated with mRNA vaccines. Efficacy was compared over periods from early March to early May and from late June to early August.
During this time, the effectiveness against infectiondecreased from 75 to 53% (other indicators were not calculated), but there is a caveat: nursing homes were obliged to report the number of vaccinated only in June, so the comparison may be inaccurate.
Another study analyzed data onNew York State from early May to late July. Efficacy against infection decreased from 91.7 to 78.9%, but against hospitalization remained the same: 91.9–95.3%.
It is noted that the most serious decline in efficiencyoccurred in a group of 18-49-year-olds: they are less likely to take precautions and are more likely to meet other people. This is in contrast to Israel, where the effectiveness against infection fell among those who are 65 years old and over.
The third study compared the effectiveness of mRNA vaccines against hospitalization based on data from hospitals in 18 states. 2–12 weeks after vaccination it was 86%, and after 13–24 weeks it was 84%.
True, most cases of COVID-19 were in the alpha strain, and in the delta, which has since practically supplanted other varieties of coronavirus.
How AstraZeneca fights new COVID-19 variants
Also Oxford University compared how the effectiveness of the Pfizer/BioNTech and AstraZeneca vaccines changes
Two weeks after the second dose, efficacywas higher for the Pfizer / BioNTech product, but in three months the rate decreased more than for the AstraZeneca vaccine. It is possible that in four to five months the effectiveness will be equal.
The authors suggested.that's because the different types of vaccine work: AstraZeneca is a vector vaccine that delivers literally one blueprint for mRNA into the cell. Further, the cells themselves produce it, so the amount can be higher, and the immunity is more stable.
Does Moderna cope with the delta strain and the rest?
A study of mRNA vaccines conducted in the United States inFebruary-June, showed that the effectiveness of Moderna's drug against infection decreased from 91 to 76%. Pfizer/BioNTech showed worse results - from 89 to 42%.
Another study in Qatar, where they testedeffectiveness of the vaccine against the delta strain, found that Moderna was again better than Pfizer—it was noted that one dose of Moderna contains about three times more mRNA.
How Sputnik V proved to be during the distribution of new versions of COVID-19
The indicator of the effectiveness of the Russian vaccine against coronavirus "Sputnik V" is reduced by 2.6 times against the Indian (delta) strain.
We see that with respect to the delta strain, there is a slight decrease in serum activity - this is approximately 2.6 times for Sputnik V.
Denis Logunov, developer of the drug and deputy director of the Center named after. N. F. Gamaleya
The efficacy of the Sputnik V vaccine againstcomplications requiring hospitalization is 81%, according to a study of St. Petersburg scientists from several universities and hospitals. According to preliminary data, 3.4% of fully vaccinated patients are admitted to hospitals.
As scientists have found, vaccination is the mosteffective for women (84%) than for men (76%). Also, the effectiveness of vaccination increases in patients over 50 years old (82%), and in patients aged 18–49 years, it is 63%.
How vaccines against new strains are being modernized
- Pfizer
Pfizer has partnered with German BioNTech to developa vaccine against the delta strain of coronavirus. The companies are now preparing an updated BioNTech drug, Pfizer, which is especially effective against this variation of COVID-19. The first batch of the new vaccine will be produced at a plant in Mainz, Germany. When the vaccine goes into civilian circulation, it is not reported.
Pfizer has a three-month window of opportunity.to develop a vaccine against the COVID-19 strain, the company noted. This process takes 95 days, starting from the day the strain of concern is identified.
- "Sputnik V"
The Sputnik V vaccine was modified to"delta" strain of COVID-19, but its effectiveness is still unknown. The developers already have samples of the new drug, said the head of the Center. Gamaleya Alexander Gintsburg.
He added that so far no one can saywhether adapted vaccines will better cope with the delta option. According to Gunzburg, this strain dominates in Russia, and it is with this that the high mortality rates in the country are associated.
Vaccines based on the original Wuhan strainmay turn out to be less effective against delta, so updating the drug makes sense, says Igor Krasilnikov, director of the Scientific and Educational Center for Immunobiotechnology at St. Petersburg University of Chemistry and Pharmacy.
- AstraZeneca
AstraZeneca and the University of Oxford began developing a modified COVID-19 vaccine against the beta strain in late June.
During the tests it is planned to check howA similar vaccine works on people who have already been vaccinated against coronavirus, as well as on those who have not yet been vaccinated. Residents of the UK, South Africa, Brazil, and Poland are participating in the trials. The new drug is developed based on the classic version of the AstraZeneca vaccine. The first test results are expected to arrive later in 2021.
Head of Scientific Expertise of a Venture FundInbio Ventures Ilya Yasny said that it is not difficult to process vaccines, but production may be delayed. It's not just about scaling up, it's about doing clinical research to see if a vaccine actually works better or worse.
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