Can you still get Covid-19 after having the vaccine?

Millions of Americans have now received at least one dose of an available Covid-19 vaccine across the country, but questions still remain about what protection this vaccine will give those vaccinated.

No matter which vaccine one receives, the immunity protection takes time to develop within the body to experience the full impact of the inoculation. For those who received Pfizer, they have to wait three weeks prior to receiving their second dose. Moderna vaccines require three to four weeks time before receiving the second dose.

While the first dose of either vaccine provides some immunity for the recipient, it’s advised to receive the second dose within the recommended time frame for full benefits.

According to clinical data, the Pfizer vaccine is 95 per cent effective in preventing Covid-19 disease two weeks after the second dose of the jab. Moderna's vaccine is 94 per cent effective in preventing Covid-19 disease two weeks after the second dose.

The single-dose Johnson & Johnson vaccine, which the Food and Drug Administration (FDA) ahas recommended states to pause use due to several blood clot cases, is 66 to 72 per cent effective in preventing Covdi-19 disease about two weeks after the jab.

None of the three vaccines provide 100 per cent effectiveness against Covid-19 illness, based on clinical date, which means it is still possible, even if it's a small possibility, for someone to contract and display Covid-19 symptoms.

"You will see breakthrough infections in any vaccination when you're vaccinating literally tens and tens and tens of millions of people. So in some respects, that's not surprising," Dr Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, said during a White House Covid briefing on 26 March.

The Centers for Disease Control and Prevention (CDC) released a report that found the two-dose Pfizer and Moderna vaccine regimen prevents 90 per cent of infections two weeks after the second dose, meaning a majority of recipients are unable to contract the virus and thus spread it to others.

In the study, released 2 April, 2,479 vaccinated individuals were monitored and researchers found only three had confirmed coronavirus vaccinations after they were fully vaccinated.

While the vaccines are not 100 per cent effective against Covid-19, they are beneficial at preventing severe disease that causes hospitalisation and/or death.

Health experts have said that people who contract Covid-19 after being fully vaccinated will likely be asymptomatic or experience mild symptoms, which shows how the benefits of the antibody response the vaccines spark within the body.

In Johnson & Johnson's clinical trial, for example, the vaccine was 85 per cent effective at preventing severe disease from Covid-19, and no one who received the jab was hospitalised or died from the novel virus.

Additionally, the Pfizer and Moderna vaccine have been proven to be 90 per cent effective against people contracting Covid-19 after they become fully vaccinated.

One concern about the breakthrough vaccines is the potential of a vaccinated person still spreading the novel virus to unvaccinated individuals, thus putting people at risk before they have access to a vaccine. But studies have shown that the vaccines are highly effective at preventing transmission from vaccinated to unvaccinated individuals.

Studies are ongoing about how long immunity lasts after people are fully vaccinated against Covid-19.

Recent data released by Pfizer has indicated the immunity from its vaccine lasts at least six months after the second dose. In the study, there was minimal antibody decline after six months. Similarly, results from Moderna showed that participants had a high level of antibodies in their system after six months of becoming fully vaccinated.

Critics have taken this information and concluded that means the vaccines only offer six months of protection against the novel virus, but this conclusion is incorrect.

Given these are breakthrough vaccines that have only been administered to large segments of the public since December, the data is limited for researchers to determine how long immune response lasts. Experts hypothesis immune response could last months longer.

Covid-19 variants are also another variable experts are considering when determining vaccine immunity. Several highly transmissible variants are circulating the US and around the world, but there is no indication these will diminish vaccine efficacy.

Pharmaceutical companies are researching potential booster shots to their vaccines that would increase someone's antibody count in the future, which could be used if antibody count and vaccine efficacy diminish.

The CDC advises for vaccinated individuals to continue to wear their masks, avoid large crowds, stay away from poorly ventilated spaces, and remain six feet from others while more and more people receive one of the available vaccines.

There are some exceptions, though, to these rules.

Vaccinated individuals are allowed to skip wearing the mask while at home or in a small gathering with other vaccinated people. CDC guidelines also allow vaccinated individuals to avoid wearing a mask when in a private space with another household who is not vaccinated.

Travel is also allowed for vaccinated individuals.

CDC guidelines say that vaccinated individuals can travel domestically and internationally without receiving a test before the trip. Individuals also no longer have to quarantine after domestic and international travel.

But some guidance, such as mask wearing, still remains unchanged from the federal health agency as researchers work to learn more about how the vaccines protect against the novel virus.