8. The COVID-19 vaccine
COVID-19 vaccines protect you against catching the disease. Vaccinated people have a reduced risk of developing the illness and its consequences. They are less likely to be admitted to hospital with COVID-19.1
If you get vaccinated, you may also protect people around you, particularly if you have friends or family who are at increased risk for severe illness from COVID-19.
Vaccination is important even if you have already had COVID-19. It can make it less likely that you will get COVID-19 again and may protect you better against new variants of the disease2.
Effectiveness
COVID-19 vaccines have been found to have effectiveness4 of around 70-90%. People who are vaccinated are up to 90% less likely to become infected than those who are not vaccinated.
Those who still get COVID-19 despite having the vaccine are likely to have a milder case of disease and are less likely to have long term symptoms.5 The effectiveness of vaccination reduces over time, and may also be lower for some new variants, so booster doses are recommended.
Vaccines
Several different vaccines are being used to protect against COVID-19. Others may be available soon. Some COVID-19 vaccines use a very small piece of virus to prompt the body to produce antibodies. Others use genetic information from the virus (RNA or DNA) to encourage the body to make harmless copies of the viruses’ protein spike and then to react by producing antibodies.3
Dose
Some vaccines only need one dose, most need two to provide the best protection. Your COVID-19 vaccine starts to work about two weeks after you have the vaccine.
Further booster doses are recommended to help your body maintain good immunity .
Variants
COVID-19, like other viruses, constantly changes to form new variants. These have been given names such as Alpha, Delta and Omicron. They may be more infectious than the original virus and might cause different symptoms. They might be more or less likely to cause serious illness.
Current vaccines work well against some variants but offer less protection against others. Additional (booster) doses of vaccine can increase protection against new variants.
Some vaccines are being adapted to take account of variants as we learn more, in the same way that the flu vaccine is modified each year.6