Omicron: How effective are two doses of Kovid vaccine compared to three

This comes as evidence emerges that the protection in the highly infectious Omron variant has the potential to outweigh the two vaccine doses offered.

So, how effective are two doses compared to three against Omicron?

Let’s break it down.

Two doses do not protect against Omicron much

vaccine protection omicron has been reduced for two reasons.

First, the antibodies generated by vaccination gradually decrease over time. Now there are many countries that have been more than a year into their COVID vaccine rollout, with so many people getting their second COVID jab six months ago.

Without the increase, their antibody levels would have dropped significantly. Australia were a little slow off the mark – but now find themselves in a similar situation.

The second reason is that Omicron can evade vaccine-induced immunity because of its constellation of mutations. Its spike protein (the bit that helps the virus reach our cells) is quite different from the delta and original viruses from which our vaccines are based.

The important part of the spike protein is the “receptor binding domain”. It attaches to a protein on our cells called ACE-2 so that the virus can gain entry. Delta had two mutations in the receptor binding domain, and three in beta. Omicron has 15 mutations in its receptor binding domain. As a result, only some of the antibodies induced by the vaccine will still bind to the oomicron’s spike and block it from getting into your cells.

For these reasons, emerging evidence suggests that two doses of a COVID vaccine five to six months after the second jab provides just 0-10% protection against infection with Omicron.

So, you can’t really claim that you’re “fully vaccinated” with just two doses right now, especially if it’s been months since your second dose.

Some protection against serious illness and hospitalization remains in place. UK data shows that two doses of AstraZeneca or Pfizer provide about 35% protection against hospitalization for up to six months after the second dose.

What about three doses?

Taking a booster dose increases your antibodies—which is especially important for Omicron because only some of those antibodies are protective. Emerging evidence suggests that protection against symptomatic Omicron infection is restored to 60–75% two to four weeks after a Pfizer or Moderna booster dose.

However, the protection of the third dose also decreases to 30–40% against Omicron infection after 15 weeks.

So, unfortunately breakthrough transitions will still be common. Fortunately, the protection from hospitalization is very high, up to about 90% after a Pfizer booster dose and drops to only 75% after 10–14 weeks, and to 90–95% by nine weeks after the Moderna booster. .

Pfizer and Moderna are currently developing vaccines that match Omicron, which, if approved, should produce better immunity against this type.

How much protection is provided by taking the third COVID vaccination dose? COVID-19 protection by severity; Second versus third dose of Pfizer, Moderna or AZ vaccines against COVID-19.

Will we need a new dose every three months?

Israel is currently giving a fourth dose of Pfizer to certain high-risk groups.

Some will be concerned that this trend means we will need a new dose every few months. But I don’t think that will happen.

We can’t promote people every few months chasing weak immunity. It is possible that trust in vaccines may decrease with each round of increase. It is worth remembering that we have never tried vaccination against a respiratory coronavirus, so we are still learning how to generate protective immunity.

There is also the ethical question of introducing multiple rounds of booster doses in wealthy countries, when many people in some parts of the world have not yet received their first two doses.

While countries with low vaccination rates have high levels of infection, all countries are at risk of outbreaks, especially if new viral variants emerge – which is certain to happen if transmission is so high globally.

But better vaccines are coming. Universal COVID vaccines are in development, targeting regions of the virus that do not mutate easily, meaning they will likely be effective in different forms.

In the future, we may get an annual COVID vaccine along with the flu vaccine. Treatment will also improve, so you can ease symptoms at home.

These developments will reduce the impact the virus has on us, so eventually COVID will stabilize to a predictable level of transmission that does not cause disruption – that is, it becomes endemic.

Your existing immunity will be boosted every year with naturally acquired infections being either almost always asymptomatic or with very few (cold-like) symptoms.

However, for more vulnerable people, such as the elderly and those whose immunity is compromised or who have chronic diseases, vaccines are less effective and the virus will still be able to cause severe illness and death, similar to the flu. We therefore need to continue progressing research into new treatment approaches that will better protect these individuals.

a silver lining

A silver lining for COVID-19 has intensified research efforts towards vaccines and treatments.

We are seeing a number of new anti-viral drugs being approved that will reduce illness and death.

Some of these treatments are likely to be effective not only in different viruses covid,

And mRNA vaccine technology could churn out new vaccines in a matter of months, something that was completely incomprehensible two years ago.

This means we are better prepared against COVID, but also future respiratory virus outbreaks and pandemics, whether it is a new coronavirus, influenza virus or any other respiratory virus.

This story has been published without modification in text from a wire agency feed. Only the title has been changed.