The answer to this is more complicated than one thinks and centers on the question of the strength and longevity of the immune response.

Scientists develop a vaccine against the coronavirus disease in Saint Petersburg (photo credit: REUTERS)
Scientists develop a vaccine against the coronavirus disease in Saint Petersburg (photo credit: REUTERS)


In recent weeks, Israel has signed two agreements to be among the first to receive COVID-19 vaccines when they become available, first with Moderna and then with Arcturus.

Will a vaccine for the novel coronavirus be a “cure-all” solution to the pandemic?

The answer to this is more complicated than one thinks and centers on the question of the strength and longevity of the immune response.
Earlier this month, a team of researchers at Tel Aviv University examined the development of antibodies binding to two different targets on the coronavirus in patients and found that, in the long run, those both with severe and mild cases of COVID-19 developed antibodies at the same level.

“Patients with mild, moderate and severe COVID-19 all developed the same level of antibodies,” said Prof. Ariel Munitz of the Department of Microbiology and Clinical Immunology at TAU’s Sackler School of Medicine in a release. “This is important, because one might have thought that the severely ill became so sick because they did not develop a sufficient amount of antibodies, and were thus unable to combat the virus effectively.”

Moreover, the research showed that levels of the antibody targeting the viral spike protein that binds the virus to human cells remained high in the patients’ blood for the first two months following contagion – possibly indicating the formation of immunological memory.

These “IgG-type antibodies play an extremely important role in the immune response because they can neutralize the protein that binds the virus to human cells to enable contagion – thereby preventing the virus from penetrating the cells,” explained Prof. Motti Gerlic, who worked with Munitz on the study. He said that his team has not yet examined how these antibodies actually work and they still do not know whether or not they neutralize the virus, “but the facts that these antibodies are quickly produced in all patients, and stay in the blood for a long time, suggest that they provide some level of immunity.”

But not all scientific research has yielded the same results and here, too, there are still many questions.

According to Prof. Cyrille Cohen, vice dean of the Mina and Everard Goodman Faculty of Life Sciences at Bar-Ilan University, multiple studies, including a recent one published by King’s College London, found that neutralizing antibodies declined significantly after a few months, which calls into question the extent to which immunity to the virus is long-lasting.

“People all over the world … already found out that a large fraction of patients who were ill, recovered and had a detectable antibody response, [but] in matter of three months or so the antibody levels were reduced, sometimes to undetectable levels,” Prof. Itay Ben Har, acting director of Tel Aviv University’s new Center for Combating Pandemics, told the Post.

“This would not be surprising,” Cohen said, explaining that there are seven known members of the coronavirus family and four of them cause common colds to which our bodies do not necessarily mount long-lasting immunity.

“This explains why sometimes we may be sick with the same disease, the same cold, several times during our lives,” he said.

On the other hand, he added, the scientific community has not yet explained why some people seem already “immune” to COVID-19, meaning they become infected but develop few or no symptoms.

He said this could be a result of some kind of cross reaction, meaning that “because you mounted a good response to a common cold caused by another member of the coronavirus family, you now have some immunity to COVID-19.”

It could also be that these people “have a good T cell response,” he said.

Indeed, growing evidence suggests that T cells provide the strongest and longest-lasting immunity to the novel coronavirus and that people who recover from corona could show no detectable antibodies but strong T-cell responses – something that is still being researched.

Most of the major vaccine makers for now said that their vaccines elicited some kind of immune response, similar to the responses seen in people who have recovered from the virus.

So, then the question is for how long will the vaccine be effective?

“We have vaccines that require boosting, like the tetanus vaccine,” Ben Har said. “There are also vaccines that are short lived and need to be re-administered every year. The best known is the flu vaccine. But this is not because of failure of our immune system to make an immune memory, but because every year the virus changes.”

He said that he does not believe that coronavirus mutates so rapidly, but that some colleagues disagree, and “at this point, we cannot really say which people are right.”

“I think it will be like the flu and we will have to live with it forever,” Dr. Rivka Abulafia-Lapid, a senior virology lecturer at the Hebrew University of Jerusalem, told the Post, describing a future where a committee meets each year to decide on what strains of coronavirus are likely to attack. She also said it could be that different strains would appear in different parts of the world.

“The people most likely to develop severe cases will need for sure to get vaccinated,” she said.

Therefore, the vaccine would not be a cure, just a preventative measure for that year, Abulafia-Lapid speculated.

But an insider with ties to the National Institutes of Health said that he is confident the vaccines will work at least in some capacity. He noted that sometimes vaccines do not prevent diseases but reduce their severity and the likelihood of dying from them, which would be a good start for any coronavirus vaccine.

He described the vaccine candidates currently in development as “vaccines 1.0” and said any vaccine that is revealed in the next year will not be perfect, but rather will need further development going forward.

As reported by The Jerusalem Post