Benefits and risks of COVID-19 vaccines.

Cactus in Arizona. (Dr. Noorali Bharwani)
Cactus in Arizona. (Dr. Noorali Bharwani)

“There is solid medical and scientific evidence that the benefits of vaccines far outweigh the risks. Despite this, there have been concerns about the safety of vaccines for as long as they have been available in the U.S,” says Centre for Disease Control and Prevention (CDC) on its website under the title of Vaccine Safety.

“Vaccine risks are rare,” according to Dr. Supirya Sharma. She said this last year. She is a senior medical advisor for Canada’s health department. “The benefits outweigh the potential risks, but it is still a drug and still a vaccine and there are potential risks even if they’re rare,” Sharma said. “That’s why we continue to monitor it.”

Sharma has said that the three vaccines authorized in Canada so far offer excellent protection and, along with public health measures, can help slow the spread of the virus and potentially help stop it from mutating even further.

“We knew this was going to happen, that we would have variants,” she said, in an interview with The Canadian Press.

There is still a lot we are learning about COVID-19 vaccines.

We know that COVID-19 has caused very serious illness and death for a lot of people.

The biggest benefit is vaccines vastly reduce your chances of getting COVID-19. They also to an even greater degree protect against hospitalisation and death. We don’t know how long protection lasts for those who are vaccinated. It’s concerning seeing breakthrough infections, and the worry is that they might increase if vaccine protection does, as suspected, fall over time.

The US Centers for Disease Control and Prevention led a nationwide study of vaccination involving more than 3,600 adults hospitalized for Covid-19 between March and August.

The study found Pfizer vaccine provided 88 per cent protection against hospitalization, and Moderna was 93 per cent effective. Johnson & Johnson’s Janssen vaccine comes in third, but still provides 71 per cent protection.

Vaccine failure

According to an article in The Conversation Canada (September 9, 2021) titled “Four factors that increase the risk of vaccinated people getting COVID” are:

  1. Vaccine type
  2. Time since vaccination
  3. Variants
  4. Your immune system

Two weeks after your second COVID-19 vaccine dose, the protective effects of vaccination will be at their highest. At this point, you’re fully vaccinated. If you still get COVID-19 after this point, you’ve suffered a “breakthrough” infection.

In the UK, research has found that 0.2 per cent of the population – or one person in every 500 – experiences a breakthrough infection once fully vaccinated. But not everyone is at the same risk. Four things appear to contribute to how well you are protected by vaccination.

1. Vaccine type

The first is the specific vaccine type you received and the relative risk reduction that each type offers. Relative risk reductions for the Moderna vaccine reduced a person’s risk of developing symptomatic COVID-19 by 94 per cent, while the Pfizer vaccine reduced this risk by 95 per cent. The Johnson & Johnson and AstraZeneca vaccines performed less well, reducing this risk by about 66 pr cent and 70 per cent respectively.

2. Time since vaccination

It’s becoming increasingly evident that length of time since vaccination is also important and is one of the reasons why the debate over booster immunisations is growing in intensity.

Some reports suggests that the Pfizer vaccine’s protection wanes over the six months following vaccination. Report from Israel also suggests that this is the case. It’s too soon to know what happens to vaccine efficacy beyond six months in the double vaccinated, but it’s likely to reduce further.

3. Variants

Current information suggests the vaccines are slightly less protective against variants.

4. Your immune system

If your immunity is compromise due to your age or other medical conditions, you will have lower levels of vaccine-induced protection against COVID-19. This raises the question – who should get a booster shot?

There is solid medical and scientific evidence that the benefits of vaccines far outweigh the risks. Get your shot and don’t forget the importance of wearing your mask, washing your hands and maintaining social distance.

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