The Omicron variant is threatening yet another viral tsunami in Israel and the world, and scientists are scrambling to determine if the vaccines can stop the storm.
The mutation has more than 50 mutations, including over 30 on the virus’s spike protein, meaning it has changed substantially since the original Wuhan strain that the Pfizer vaccines target.
Preliminary studies are starting to show how these alterations impact the effectiveness of the coronavirus shots. However, the situation is confusing as the studies are small and limited. The majority of tests were conducted in labs and their results, therefore, are not based on real-life data.
And with the majority of new Omicron cases in Israel occurring in people who were fully protected – meaning they had three jabs or recovered within the last six months – one could wonder whether vaccination is even worth it.
“We have to make a clear distinction between neutralization tests in the laboratory using antibodies from people who were either vaccinated or recovered and real-life events such as contamination, symptomatic infection, hospitalization and severe disease,” said Prof. Cyrille Cohen, head of the immunotherapy lab at Bar-Ilan University.
So far, we know Omicron is much more infectious than even the Delta variant – four times as much, according to at least one study.
Moreover, it appears the antibodies of both vaccinated and recovered people are not working as well against Omicron as before. Research shows two doses are likely not enough, whether they were administered recently or longer ago, but that three could be better.
“I think some consider that three doses may still be relatively effective and to some extent may at least partially prevent symptomatic disease,” Cohen said. “But most agree that in terms of severe disease, the chances will be minimized by three doses.”
So how come the majority of cases here are people who are fully vaccinated – 81% of the country’s 67 cases as of Sunday night?
That’s because the majority of Israelis who were diagnosed with carrying the variant had either been abroad or in direct contact with someone who had been, and the vast majority of citizens who are traveling in and out of Israel are fully vaccinated or recovered.
Eighty-seven percent of Omicron cases in Israel came back from abroad or were in direct contact with these individuals. In contrast, only 13% of Omicron cases simply caught the variant locally.
To date, there are 4 million Israelis who have received three jabs and only 1 million who took two jabs more than five months ago and have not received their third shot.
Since most people traveling have been vaccinated with three doses, the chances of exposure of an unvaccinated person compared to a vaccinated person are extremely different. Unvaccinated people have tended to travel less in the last two weeks because of the strict isolation requirements on anyone who is not inoculated.
Finally, there are no severe cases among the vaccinated so far. Head of Public Health Services Dr. Sharon Alroy-Preis said that only one of the 55 cases diagnosed as of Saturday night was in serious condition in general, and that person is unvaccinated.
THE RECENT STUDIES are all a little different but they are starting to align.
The most recent one was published over the weekend by the UK Health Security Agency, which analyzed more than 500 people who were infected with the Omicron variant – each had either two doses of the AstraZeneca or the Pfizer vaccine. The study showed a striking reduction in neutralizing activity against Omicron.
However, when people received a booster shot, protection against symptomatic infection shot up to 70% for those who got AstraZeneca and to 75% for those who had three Pfizer shots.
That is still lower when compared to the protection level of the booster shot against Delta, which was at 90%.
The UK study also showed as much as an eight-fold increased risk of reinfection.
Also, over the weekend, more information was revealed about a study conducted last week in South Africa by the Africa Health Research Institute in Durban. That study involved blood samples of only 12 people, which were tested against a two-shot course of Pfizer’s vaccine. The study showed the vaccine may have just 22.5% efficacy against symptomatic infection from the Omicron variant.
It also found a more than 40-fold reduction in levels of neutralizing antibodies produced by people who received the Pfizer vaccine against Omicron than the original Wuhan strain.
However, it did show that the shots could ward off severe disease.
These findings were all similar to a study conducted by Pfizer and one released late Saturday night in Israel by Sheba Medical Center.
Pfizer reported last week that preliminary laboratory studies demonstrate that three doses of its COVID vaccine neutralize the Omicron variant, while two doses appear to be significantly less effective. Specifically, the research showed that the immunity offered by the third dose against Omicron was 25-times higher than the immunity offered by two doses.
Sheba, similar to the UK study, showed that the neutralizing ability of even three shots of the Pfizer vaccine is four times less against Omicron than Delta, but much better in comparison to two shots taken more than five months ago in which there was “no neutralization ability whatsoever,” according to Prof. Gili Regev-Yochay, director of the Infectious Disease Epidemiology Unit at the hospital.
There were similar small studies released in Germany and Switzerland.
THE QUESTION, therefore, is not whether or not vaccination works but whether or not one should jump to get a third or even fourth shot of the existing Pfizer vaccine.
Health officials were planning to debate late Sunday night whether to recommend a booster shot for Israelis only three months instead of five after their second shot. Health Ministry Director-General Nachman Ash said experts will also soon debate whether a fourth shot should already be administered to the country’s most vulnerable.
Cohen said it is too preliminary to make such decisions for the general population since we still do not even know how long the third shots last, let alone against the Omicron variant.
Moreover, Pfizer’s vaccine is still centered on the original spike protein, and therefore even a fourth dose would likely not be as effective against Omicron even if it increases a person’s level of antibodies. Vaccinating the whole population with a fourth dose is unlikely to put an end to Omicron.
Rather it would be optimal to have vaccines based on the Omicron spike protein.
Pfizer has said such a vaccine could be ready in a few months. But by then, it is possible the world would already be dealing with whatever variant comes after Omicron.
“I don’t know what a fourth shot will do to the young 25- or 30-year-old man in terms of myocarditis, for example,” Cohen said. “So, right now, I would not take the risk.”
Tel Aviv University’s Dr. Oren Kobiler said these studies are still too small and too early to provide solid answers.
“We don’t know anything,” Kobiler stressed. “The ability of antibodies to inhibit the vaccine or stop the virus or variant in a test tube” is not the same as in real life. “Our immune system is much more than neutralizing antibodies.”
He said the results of most of these tests should not be used to set policy.
“We need patience,” Kobiler said.
IT SHOULD also be noted that Israel does have some advantages going into this wave than previous waves, including that 60% of the public have already been vaccinated at least in some capacity.
In addition, it appears according to data in the UK, that the Omicron variant, while more infectious, is causing less severe disease and less death.
Moreover, there are now life-saving drugs such as those by Merck, Pfizer and Regeneron that could help stop severe disease in the country and the world as they become available.
But even with these benefits, experts agree that now is not the time for complacency, but rather to wear masks, social distance and go out and get the jab.
Ash said there are around 3 million Israelis who could get vaccinated right now: a million eligible for the booster, 700,000 who have not gotten vaccinated at all and the rest are children between the ages of five and 11.
It will be at least another week until there is clearer data as to how effective the vaccine is against stopping infection, Kobiler said, and another two or three weeks until its complete ability to stop serious disease is understood.
So in the meantime, he stressed, “get your booster shot. Get your kid vaccinated. And keep masking.”