The second dose of the COVID-19 vaccine is crucial for several reasons:

  1. Boosting Immune Response: The first dose of the vaccine primes your immune system to recognize and respond to the virus, but the second dose serves as a booster. It helps to further strengthen and enhance the immune response generated by the first dose.
  2. Increased Protection: Clinical trials have shown that two doses of the COVID-19 vaccine offer significantly higher levels of protection against the virus compared to a single dose. The second dose helps to provide more robust and longer-lasting immunity.
  3. Variants and Immune Escape: Some variants of the virus that causes COVID-19 can partially evade the immune response generated by a single vaccine dose. The second dose helps to provide a broader and more effective immune response, reducing the risk of breakthrough infections caused by variants.
  4. Memory Immune Cells: The immune system generates memory cells after exposure to the virus or the vaccine. These memory cells “remember” the virus and can quickly mount a strong defense if you’re exposed again. The second dose helps to boost the number of memory cells, providing better protection against future infections.
  5. Clinical Trials and Efficacy: The clinical trials for the COVID-19 vaccines have established the two-dose regimen as the recommended schedule for achieving the highest levels of vaccine efficacy and protection. Deviating from the recommended dosing schedule could impact the vaccine’s overall effectiveness.
  6. Public Health and Herd Immunity: Achieving widespread vaccination and building herd immunity is a crucial step in controlling the spread of the virus. Two doses of the vaccine, as recommended by health authorities, contribute to reaching the threshold required for effective herd immunity.

vaccine first dose

Get the second dose
What it comes down to is that receiving only one dose of a two-dose COVID-19 vaccine is not as useful as receiving the full series. Given the spread of the virus and its variants and the serious health risk it poses, the second dose is strongly recommended.
When you’re fully vaccinated – 14 days from receiving the second dose of either Pfizer or Moderna or the one-dose vaccine from Johnson & Johnson – you’ll be able to start doing a lot of the activities you haven’t been able to do throughout the pandemic.