Yes. Even those who have allergies to penicillin, antibiotics or types of medications are not at risk if they get a COVID-19 vaccine.

The UK regulator says anyone with a history of severe reactions to food, insect bites or a drug or vaccine can safely receive Covid vaccine as long as they are not allergic to any ingredient in the vaccine.

The vaccine should also not be given to anyone who has had a previous ‘systemic allergic reaction (including immediate onset anaphylaxis)’ to ‘any component of the vaccine’, or who had such a reaction to their first dose of the vaccine.

The Oxford-AstraZeneca vaccines should not be given to those who have had a previous severe allergic reaction to:

• A previous dose of the same COVID-19 vaccine
• An ingredient in of the COVID-19 vaccine

Hypersensitivity

As with all injectable vaccines, appropriate medical treatment and supervision should always be readily available in case of an anaphylactic event following the administration of the vaccine.

The vaccine should also not be given to anyone who has had a previous ‘systemic allergic reaction (including immediate onset anaphylaxis)’ to ‘any component of the vaccine’, or who had such a reaction to their first dose of the vaccine.

Concurrent illness

As with other vaccines, administration of COVID-19 Vaccine AstraZeneca should be postponed in individuals suffering from an acute severe febrile illness. However, the presence of a minor infection, such as cold, and/or low-grade fever should not delay vaccination.

Thrombocytopenia and coagulation disorders

As with other intramuscular injections, COVID-19 Vaccine AstraZeneca should be given with caution to individuals with thrombocytopenia, any coagulation disorder or to persons on anticoagulation therapy, because bleeding or bruising may occur following an intramuscular administration in these individuals.

Immunocompromised individuals

It is not known whether individuals with impaired immune responsiveness, including individuals receiving immunosuppressant therapy, will elicit the same response as immunocompetent individuals to the vaccine regimen.

Interchangeability

No data are available on the use of COVID-19 Vaccine AstraZeneca in persons that have previously received a full or partial vaccine series with another COVID-19 vaccine.

Drug Interaction

No interaction studies have been performed.

Concomitant administration of COVID-19Vaccine AstraZeneca with other vaccines has not been studied.

Yes. According to the Advisory Committee on Immunization Practices (ACIP), the independent committee noted that data from clinical trials suggests that vaccination is "safe and likely efficacious" in people who have previously been infected with COVID-19, whether they displayed symptoms or not.

"Significant reductions in neutralizing antibodies are seen even within the first few months after recovery from a COVID-19 infection," he says. This suggests that vaccination could be beneficial, regardless of whether you had a mild or severe form of COVID-19.

When people who've already had COVID-19 get vaccinated, their immunity is effectively topped up, meaning they're hopefully protected for longer. And even after people have been vaccinated, it's possible they'll need additional booster doses to keep their immunity up.

"Discussions are ongoing regarding the possible need for high-risk individuals to receive booster vaccinations every six or 12 months, but more data is needed. Due to the severe health risks associated with COVID-19 and the fact that re-infection with COVID-19 is possible, vaccination is needed regardless of whether person already had COVID-19 infection.

The MHRA has considered the issue and decided that getting vaccinated is just as important for those who have already had Covid-19 as it is for those who haven’t.

The committee also notes that current evidence suggests that COVID-19 reinfection is uncommon in the 90 days after initial infection, so people with documented acute infection in the preceding 90 days may delay the vaccine until the end of this period, if they wish.

Yes. The ChAdOx1 nCov-2019 coronavirus vaccine, developed by teams at the University of Oxford, has been shown to trigger a robust immune response in healthy adults aged 56-69 and those over 70 years of age. The data, published in The Lancet, suggest that one of the groups most vulnerable to serious illness, and death from COVID-19, could build immunity.

COVID-19: Oxford vaccine produces ‘robust’ response in older adults. According to researchers, volunteers in the trial demonstrated similar immune responses across all age groups.

The latest trial results suggest that the University of Oxford’s coronavirus vaccine produces a strong immune response in older adults.

The official guidance says everyone should get the same vaccine for both doses.

In very rare circumstances - if only one vaccine is available, or it's not known which was given for the first dose - a different vaccine can be used.

As with all the vaccines being developed against coronavirus, scientists don't know yet.

It’s not known yet for how long the Oxford vaccine, or any other coronavirus vaccine for that matter, provides protection. Some vaccines are effective for years, but for obvious reasons this will take longer to confirm. But early evidence has suggested immunity to the virus can wear off or diminish over time and can vary considerably from person to person.

Experts do not know how long antibodies last in a person’s system, how strong they may be, or whether their development depends on the severity of a person’s illness.

It may be that people need annual vaccinations, as happens with the flu vaccine.

One big question surrounding all of the coronavirus vaccines is whether they prevent asymptomatic infections as well as illness caused by the virus. The Oxford data found some evidence of reduced asymptomatic infections in those who received the half-dose followed by a full dose later.

The ACIP recommends that vaccination should be deferred until recovered from acute illness (if experiencing symptoms), and should've completed the isolation period. For most people, that's 10 days after the onset of symptoms, provided there's been no fever for at least 24 hours, per CDC guidelines.

The committee also notes that current evidence suggests that COVID-19 reinfection is uncommon in the 90 days after initial infection, so people with documented acute infection in the preceding 90 days may delay the vaccine until the end of this period, if they wish.

Yes. It typically takes a few weeks for the body to build immunity (protection against the virus that causes COVID-19) after vaccination. That means it's possible a person could be infected with the virus that causes COVID-19 just before or just after vaccination and still get sick. This is because the vaccine has not had enough time to provide protection.

“The information in this article is accurate as of publication time. However, as the situation surrounding COVID-19 continues to evolve, it's possible that some data may have changed since publication.”

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