What to Know About The COVID-19 Vaccines

A West LA pharmacist with a COVID-19 vaccine.
What to Know About The COVID-19 Vaccines

Vaccines are one of modern medicine’s most effective tools, and the three COVID-19 vaccines are already making a huge impact on transmission of the virus. Vaccines operate by helping our immune system develop “memory” white blood cells called T-lymphocytes that recognize a type of infection and are prepared to fight it. There are three types of vaccines that are being used as COVID-19 vaccines in the United States: mRNA vaccines, protein subunit vaccines, and vector vaccines. While these each work differently, they all give our immune systems the instructions on how to fight a virus by introducing a harmless version that our body uses to create T- and B-lymphocytes that can fight off the real virus. A pharmacist at a Santa Monica pharmacy can help you understand more about how vaccines work.

Moderna COVID-19 Vaccine

The Moderna vaccine is an mRNA vaccine produced by the Massachusetts-based biotechnology company Moderna, which specializes in mRNA medicines. The Moderna COVID-19 vaccine, like the others, has only been authorized by the FDA for emergency use in people 18 years of age or older. This vaccine was evaluated for efficacy in a study among a diverse group of participants that had zero severe cases and an efficacy estimate of 94.1%. Side effects of the Moderna vaccine include pain at the injection site, headache, fatigue, muscle and joint pain, and in rare cases allergic reactions have been recorded. The Moderna vaccine is delivered via injection in two doses, 28 days apart.

Pfizer COVID-19 Vaccine

The Pfizer vaccine is the second mRNA vaccine, produced by a collaborative effort of American pharmaceutical company Pfizer and BioNTech, a German biotechnology firm. This vaccine is also authorized under an Emergency Use Authorization, or EUA, from the Federal Drug Administration. The Pfizer vaccine underwent clinical trials beginning in Germany and the United States in April and May 2020 that determined an efficacy rate of 95% for people aged 16 and older. The side effects of the Pfizer vaccine are similar to the Moderna vaccine’s side effects and include fatigue, muscle or joint pain, nausea, chills, and fever. Like the Moderna vaccine, the Pfizer vaccine is delivered via injection, in two doses 21 days apart.

Johnson & Johnson COVID-19 Vaccine

The Johnson & Johnson/Janssen COVID-19 vaccine is the outlier among the COVID-19 vaccines, and is produced by the Belgian company Janssen Pharmaceuticals and its parent company Johnson & Johnson. The J&J vaccine is a viral vector vaccine, and is unique in that it does not need to be stored frozen and only requires one dose. This vaccine underwent clinical trials in June 2020, which determined a 66% efficacy in preventing any symptoms of COVID-19, preventing severe COVID-19 with an efficacy of 85%, and a 100% efficacy in preventing hospitalizations. The Janssen COVID-19 vaccine received an Emergency Use Authorization, but the CDC and FDA recommended a pause in the use of this vaccine due to incidences of a rare, dangerous type of blood clot in six women aged 18 to 48 who received this vaccine. The vaccine is under assessment to determine future use, so we recommend following the most recent guidelines from the FDA and CDC.


When the COVID-19 vaccine becomes available in your area, and for your criteria, it’s crucial that you seek out an appointment, regardless of which vaccine is available. Getting the COVID-19 vaccine not only helps keep yourself safe but also is an essential part of reducing the spread and helping to keep others safe. Contact your doctor or a Los Angeles pharmacy to learn more about the availability of the COVID-19 vaccine.