The findings stem from a multi-hospital analysis in the US. The researchers say that people who had a reaction after their first dose, therefore, shouldn't avoid getting the second dose. People are encouraged to complete their vaccination series even if they had an allergic reaction to the first dose of the mRNA Covid-19 vaccines by Pfizer-BioNTech or Moderna. According to researchers from Massachusetts General Hospital (MGH), a multi-hospital analysis of individuals who experienced anaphylaxis, a potentially life-threatening whole-body allergic reaction, after receiving their first mRNA Covid vaccine dose showed that they received their second dose without serious complications. Based on this, the allergists are encouraging patients to complete their vaccination series. Several studies have also underscored the importance of receiving the second dose, as the first jab offers little protection against Covid-related severe disease and death.