Keller emphasizes that recent remarks from leaders of those two pharmaceutical companies are pure speculation at this point.

The core question is whether any of Omicron’s mutations have affected the specific area where the virus binds to receptors in the cells of our bodies.

“As long as the Omicron variant does not mutate this area and bind to a different receptor, the vaccine should protect us — even if the virus replicates faster and is more infectious, in my estimation,” says Melamed.

He emphasized that no vaccine prevents infection. Rather, vaccines protect from illness following infection.

“Up to now, especially in vaccinees, disease from Omicron has been mild,” says Keller. “We were very concerned at the beginning of the Delta wave, but we saw from Ministry of Health data that in cases of serious disease above age 60, most were unvaccinated.”

However, vaccine effectiveness is weaker in people over age 60, according to a recent study from Melamed’s lab.

He explains that the immune system’s memory declines with age. If it doesn’t “remember” a pathogen it once defeated or was vaccinated against, it cannot mount an effective defense the next time that pathogen invades.

“Older individuals, even when vaccinated twice, had a higher rate of infection and that’s why it was so important for them to get a third shot,” says Melamed.

Melamed and Keller strongly urge parents to get their five- to 11-year-olds vaccinated even though children tend to get milder symptoms if they become infected.

Keller, a trained pediatrician and microbiologist, believes that eventually a shot against Covid-19 will become part of the routine childhood vaccination regimen.

Are travel restrictions helpful in stopping the spread?

Our experts disagree on Israel’s decision to prevent foreign citizens from entering the country for two weeks beginning November 28.

Although Melamed personally chooses not to travel abroad these days, he says that “closing the gates for two weeks to foreign travelers is an overreaction.”

Keller, on the other hand, finds the government’s latest Covid policies appropriate and reasonable — even if he might have chosen different policies.

He points out that the first several Delta infections in Israel were “imported” from The Netherlands. And on Monday, a fully vaccinated Sheba cardiologist developed mild Covid-19, later found to be caused by the Omicron variant to which he was exposed at a London conference.

“The government is dealing with [the new Omicron variant] in a cautious way,” Keller says. “If I return from abroad, I have to spend three days quarantining and get another PCR test, which is not a catastrophe. And it’s temporary. They will reconsider everything in about 10 days.”

He adds that Israel, like most countries, hadn’t faced pandemics for decades until Covid came along.

“Over the past year and a half, we have been learning slowly but surely and establishing new policies according to the data.”

Could Omicron be the final mutation?

Contrary to some opinions that the relatively mild Covid-19 cases from the Omicron variant indicate the SARS-CoV-2 virus is on its last legs, our experts say new variants remain a constant threat.

“Even if we get milder disease with this variant, from my understanding it doesn’t mean anything,” says Keller.

“With influenza, there are years we are facing [variants of the] viruses that cause mild disease and sometimes variants that cause severe disease.”

Keller emphasizes that “mutations are generated everywhere and spread around the globe. The next one may change the rules or the receptor binding area.”

What can we do to protect ourselves?

Vaccination is the first line of defense, say the experts.

Thanks to an aggressive campaign to provide booster shots to those inoculated at least six months previously, and vaccines to children aged five to 11, Israel is the most vaccinated country in the world.

Keller points out that unvaccinated people (including children) account for most of the reported cases during the Delta wave.

People over 60 may need more frequent boosters or a combination of different types of vaccines, Melamed speculates. “If you have [immune] memory, if you have antibodies, the viral infection will face those defenses and won’t get as far. It all depends on how ready your body is.”

Aside from inoculation, both men recommend continuing preventive protocols of social distancing, wearing facemasks at indoor gatherings and washing hands frequently.

But they also encourage people to live their lives, not to avoid getting together with friends, family and colleagues.

“We need to live with the [corona]virus as we live with influenza,” Melamed says. “There is a wise global attempt to develop medications to treat the disease and as time goes on we know better how to deal with it.”