How long after first vaccine do you get second

The NHS is now offering 2 doses of coronavirus (COVID-19) vaccine to all young people aged 16 to 17 years to help give them longer lasting protection.

You may have recently had a first dose of the COVID-19 vaccine. This guide contains information that will help you make the decision about the right time for you to get the second dose.

Young people at greater risk

Those young people who are at greater risk of serious illness if they catch COVID-19 will already have been offered 2 doses of vaccine, given 8 weeks apart.

This guide is aimed at those young people who are not considered at greater risk.

Protection from the first dose

Studies suggest that even after 1 dose of vaccine your risk of serious complications from COVID-19 infection are greatly reduced. This protection is expected to last for a few months in young people.

People who have had previous COVID-19 infection who then get 1 dose of vaccine, and those who get infected after the first dose, make a good immune response – at least as good as people who have had 2 doses. This suggests that young people who get both infection and vaccine will have high levels of protection.

Benefits of a second dose

A second dose helps to improve protection in the longer term. Further studies will help us to know how long protection will last.

• having a painful, heavy feeling and tenderness in the arm where you had your injection. This tends to be worse around 1 to 2 days after the vaccination
• feeling tired
• headache
• general aches, or mild flu like symptoms

These side effects only last a few days but are more common after the second dose.

Recently, cases of inflammation of the heart (called myocarditis or pericarditis) have been reported very rarely in the first week after the COVID-19 vaccines.

Most of these cases have been in younger men and are more common after the second vaccination.

The side effects include:

• chest pain
• shortness of breath
• feeling of having a fast beating, fluttering or pounding heart

Most people recovered and felt better following rest and simple treatments. Amongst those who get severe side effects, there may be an even smaller number in whom there are some longer-term effects. Longer-term studies are underway.

If you had myocarditis or pericarditis after the first dose, you should seek medical advice before having a second dose of the vaccine.

Timing of the second dose

The Joint Committee on Vaccination and Immunisation (JCVI) currently advises that you should have your second dose around 12 weeks after your first dose. Having a 12 week gap may extend the length of time your protection will last after the second dose.

As a precaution, the JCVI believes that a gap of 8 to 12 weeks may reduce the risk of more serious but rare side effects, like myocarditis. The JCVI also suggests that if you have had a COVID-19 infection you should wait 12 weeks before having the next dose. If you have had the first dose of vaccine and been infected, you are likely to already have high levels of protection.

These gaps may be reduced to 8 weeks if we expect protection from the vaccine or from prior infection to be reduced, for example with a new variant.

There may be other reasons for having the second dose even sooner, after 8 weeks.

These reasons include:

• if you are considered to be ‘at risk’ and have not yet had your second dose
• if you live with someone who is considered at risk and you want to help protect them
• if your circumstances, such as work or essential travel, require a second dose

If you are still unsure, you can discuss your decision with a doctor, nurse or pharmacist.

You should read the product information leaflet for more details on your vaccine, including possible side effects, on the Coronavirus Yellow Card website. You can also report suspected side effects of vaccines and medicines through the Yellow Card scheme.

Further information is available on NHS.UK.

Covishield (also called Vaxzevria) is AstraZeneca's COVID-19 vaccine. In clinical trials researchers studied how effective the vaccine was after one dose. Early results showed that the vaccine didn't produce a strong enough immune responses in trial participants, so researchers then decided to add a second shot, setting time between doses at four weeks. Those findings showed that the vaccine prevented symptomatic infections in 76% of participants 15 days or more after receiving their second shot. For adults over 65 years of age, this number was 85% and the vaccine prevented severe disease and hospitalizations in 100% of all trial participants. However, a pre-print analysis in the Lancet compared 17,000 people — some whose shots were 12 weeks apart, others whose shots were 6 weeks apart. The vaccine was more effective in people whose shots were twelve weeks apart. It appears that delaying the second dosage of the vaccine may strengthen the immune system's response to the virus. This is important because nations like the United Kingdom, India, and Spain have increased the amount of time between the first and second doses of Covishield. These nations are hoping to use their current supplies to get a greater number of people partially vaccinated, rather than a fewer number fully vaccinated. This will hopefully decrease rates of transmissions and hospitalizations so the health system is not consistently overwhelmed with COVID-19 patients. The risk with this strategy is that more "breakout" infections can occur after just a single dose. The World Health Organization recommends an interval of 8-12 weeks between the first and second doses of the vaccine. Further studies are needed to evaluate a longer amount of time between the two doses than three months.

Covishield (also called Vaxzevria) is AstraZeneca's COVID-19 vaccine. In clinical trials researchers studied how effective the vaccine was after one dose. Early results showed that the vaccine didn't produce a strong enough immune responses in trial participants, so researchers then decided to add a second shot, setting time between doses at four weeks. Those findings showed that the vaccine prevented symptomatic infections in 76% of participants 15 days or more after receiving their second shot. For adults over 65 years of age, this number was 85% and the vaccine prevented severe disease and hospitalizations in 100% of all trial participants. However, a pre-print analysis in the Lancet compared 17,000 people — some whose shots were 12 weeks apart, others whose shots were 6 weeks apart. The vaccine was more effective in people whose shots were twelve weeks apart. It appears that delaying the second dosage of the vaccine may strengthen the immune system's response to the virus. This is important because nations like the United Kingdom, India, and Spain have increased the amount of time between the first and second doses of Covishield. These nations are hoping to use their current supplies to get a greater number of people partially vaccinated, rather than a fewer number fully vaccinated. This will hopefully decrease rates of transmissions and hospitalizations so the health system is not consistently overwhelmed with COVID-19 patients. The risk with this strategy is that more "breakout" infections can occur after just a single dose. The World Health Organization recommends an interval of 8-12 weeks between the first and second doses of the vaccine. Further studies are needed to evaluate a longer amount of time between the two doses than three months.

It takes time for your body to build up an immune response after you get your vaccination.

The ATAGI recommended doses and vaccines outlines which vaccines and doses are recommended for each age and population group.

The first dose gives you partial protection as soon as 12 days afterwards. The second  dose encourages your body to create stronger protection (immunity). A third dose is required for severely immunocompromised people.

A booster dose will make sure the protection from your first doses is even stronger and longer lasting, and should help prevent spread of the virus.

It takes 7 to 14 days after a dose before you are fully protected. 

Find out more about booster doses and third doses for people with severe immunocompromise.

How long protection lasts

We do not yet know how long the protection from COVID-19 vaccines will last. Ongoing research around the world is evaluating:

• how long protection lasts
• whether you will need booster doses, such as an annual booster.

Right now you can book your booster dose if it has been 3 months or longer since your second dose of your COVID-19 vaccine.

Learn more about booster doses.

Staying up to date

To be considered up to date with COVID-19 vaccination, you must have completed all the doses recommended for your age and health status.

Find out about how to stay up to date with COVID-19 vaccines.

Get a COVID-19 digital certificate

Once you are fully vaccinated, you can get a vaccination certificate. It can take about 2 weeks after your second dose to become available.

Learn more about COVID-19 digital certificates.

Side effects

Serious or allergic reactions to vaccines are very rare. They usually occur within 15 minutes of receiving a vaccine. 

You will be monitored for at least 15 minutes after your vaccination. The person who gives you the vaccine has been trained to respond to immediate reactions.

If you have side effects of vaccination

Most potential side effects are mild and go away in a few days. Very rarely, side effects might be more serious.

Learn when you should seek help for side effects.

You can check any symptoms you are experiencing through healthdirect's symptom checker. 

Check side effect symptoms

You can also call the national coronavirus and COVID-19 vaccine helpline on 1800 020 080 any time.

Find out more about general vaccine safety and side effects, or see specific side effects associated with:

Report a suspected reaction or side effect

Reporting suspected side effects and reactions helps us monitor vaccine safety. Every report is valuable and helps ensure vaccination is safe.

If you or a health professional thinks you have experienced a reaction to or side effect of vaccination, please report it.

You can ask a health professional to report to the Therapeutic Goods Administration (TGA) on your behalf. 

Or you can report side effects yourself:

If you have experienced a rare side effect you may be eligible for compensation under our COVID-19 vaccine injury compensation scheme.