COVID-19 vaccines effectively prevent severe symptoms and deaths. Data on the vaccines' effect on the virus's transmission is currently insufficient.
The Centers for Disease Control and Prevention (CDC) states that the risks of COVID-19 infection in vaccinated people cannot be eliminated as long as there is continued community transmission of the virus. Vaccinated people could potentially still get COVID-19 and spread it to others. Research is ongoing to monitor how long a vaccinated person is likely to be protected from infection and whether they can still transmit the virus to others. People who already have COVID-19 may still benefit from the vaccination. There is currently insufficient information to confirm if or how long people can be protected from getting COVID-19 after receiving the vaccine. Early evidence suggests immunity from COVID-19 may not last very long, but more studies are needed to understand it better.
None of the vaccine companies are guaranteeing 100% efficacy. Vaccinologist Larry Corey told Nature that most clinical trials of COVID-19 have shown that it can prevent the disease. He said that vaccines could help reduce the chance of transmission, but they will only be effective if people are prevented from acquiring the disease.
There are many factors to consider while looking at how the virus is transmitted even though people are being vaccinated. Factors like lockdowns, social distancing, and other large-scale behavioral changes can also affect the data regarding transmissions. The virus can also spread from asymptomatic carriers, which makes it harder to detect such infections.
Due to a wide variety of research underway on this topic and the inconclusiveness in the available data, it is hard to say whether COVID-19 vaccines prevent transmission of the virus completely. However, the benefits of getting the vaccine to prevent getting infected and following standard pandemic measures laid out by one's own country and the WHO outweigh the risk.
The COVID-19 pandemic has given rise to a lot of potentially dangerous misinformation. For reliable advice on COVID-19 including symptoms, prevention and available treatment, please refer to the World Health Organisation or your national healthcare authority.