Why the bad news of the AstraZeneca vaccine is an obstacle to getting out of the pandemic

Many unknowns remain, as this study has not yet been fully peer-reviewed or published. What we know is that it mainly contained a relatively small number of volunteers who were young and healthy and therefore less likely to suffer from severe Covid-19 disease. In short, this study did not evaluate protection against serious illness, hospitalization, or death, and many experts suggest that these results can be prevented.

“The most important thing in the medium term is to prevent a more serious form of Covid-19, and the AstraZeneca vaccine is believed to do this,” said Dr. Peter English, an infectious disease management consultant. He told the Science Media Center in the UK.

New vaccination strategy

Ineffective vaccines may force countries where new variants predominate to change their vaccination strategies.

Instead of trying to achieve herd immunity, the focus may be on preventing as many deaths as possible, even while the virus continues to circulate.

Professor Salim Abdool Karim, Co-Chair of South Africa’s Covid-19 Advisory Board, said he is likely to take a more “step-by-step approach” to assess the effects of vaccination by talking to CNN. Stated. Out.

“The first step is to vaccinate about 100,000 people. After these vaccinations, check the hospitalization rate, and if you find that the hospitalization rate is below the threshold. That’s what we’re seeing, and you can be confident that the vaccine will work … and if so, you can continue to deploy it, “he said. Told.

“If you have more hospitalizations than you expected, you should stop, check your current location, and probably switch to another vaccine.”

However, the AstraZeneca vaccine is an important part of mass immunization programs in many countries around the world.

The COVAX program, a coalition of Gavi and the World Health Organization that aims to distribute the Covid-19 vaccine to poorer countries, relies on this vaccine. Last week, COVAX announced plans to distribute more than 337 million doses worldwide. Of these, 336 million are AstraZeneca Oxford vaccines and 1.2 million are Pfizer Bio N-Tech vaccines.

COVAX experts said Monday that the WHO Strategic Advisory Group had finalized new recommendations for the use of the AstraZeneca vaccine and would present them to the Executive Secretary on Tuesday.

South African health officials said they hope to receive their first dose of Johnson & Johnson vaccine by the weekend. The country has also ordered an additional 20 million vaccines through a contract with Pfizer / BioNTech, but it is not clear when those doses will arrive.

Nevertheless, the AstraZeneca vaccine will be the most accessible option for many countries, at least initially.

Reduce the burden of medical services

The role of the vaccine is to teach the immune system to quickly find and fight the virus. In essence, it helps the body remember the infection, so if you get infected, it acts faster. “Your own immune system also reacts to remove the virus, but without a vaccine, this reaction slows down,” said Dr. Julian Tan, an honorary associate professor at the University of Leicester and a clinical virologist. ..

Currently available coronavirus vaccines work by inducing antibodies and T cells that have been shown to fight the original coronavirus. Antibodies work by attaching to and attacking proteins on the surface of the virus. In the case of coronavirus, this is a spike protein.

Tang explained that vaccine-induced antibodies may not bind well to newer versions of the virus if the virus changes too much, especially with peplomer.

“This means that these vaccine antibodies cannot eliminate these viruses when infected, leaving behind viruses that need to be removed by your immune response. This slows down the response.” He added.

“But studies suggest that these vaccine antibodies have sufficient binding to remove at least some mutant viruses from the system-to prevent more serious illness and death.”

One of the main reasons pandemics are fatal is that the number of people in need of treatment is so large that partially effective vaccines are not ideal, but they alleviate this burden.

There are cases where the medical system is unable to keep up with the number of patients coming in. When this happens, some patients may die due to lack of access to help on time. There is also a knock-on effect throughout the system, and non-urgent treatment is postponed or canceled.

Experts argue that if a vaccine can reduce the burden of medical services, it will prove beneficial.

“This may seem like fewer people need an ICU bed and more people can recover at home,” said Dr. Oliver Watson, an infectious disease researcher at Imperial College London. In some environments, hospitals can actually have serious consequences, “he added. It is growing very much. ”

This was true for many European countries, including the United Kingdom, where the government was forced to open several field hospitals to prevent the national health system from being overwhelmed.

Vaccine adjustment

Data from South Africa is undoubtedly a setback to vaccination campaigns, but scientists are already working on updating existing vaccines, making them more effective against new variants.

AstraZeneca said on Saturday that it would work with the University of Oxford to adapt the vaccine against the B.1.351 mutant and advance the vaccine through clinical development so that it is “ready for fall delivery if needed.” Pfizer said last month that it “lays the foundation” for creating vaccine boosters that respond to coronavirus variants.

“This is always seen with flu vaccines,” said Tang. Influenza vaccines are adapted annually to target the most prevalent virus strains. Sometimes the vaccine chosen does not match the epidemic strain.

“If the vaccine season isn’t right, influenza infection, morbidity, and mortality can increase, but it’s unavoidable to some extent because the virus always mutates first. Then, the vaccine is adapted to the new virus. Need to be adjusted, “Tang added. ..

British Health Minister Matt Hancock said Monday that the flu blueprint could help with the coronavirus in the future.

“Jabs are updated annually in response to mutations and changes found in the past few months, manufactured in the summer and delivered to the arms of those most vulnerable to the flu in the fall,” he says. It was.

For Covid-19, he explained, he needed to think of ways to protect people in a similar way.

Fortunately, developing a vaccine that works against a new variant does not mean starting from scratch, so updates may be available soon.

“The genome of variant peplomer proteins is known, and the technology to” plug “the genes into mRNA and vector vaccines is well established,” said English. “We look forward to the availability of new vaccines for South African variants within a few months.”