Vaccination is considered one of the robust methods for protection and prevention of transmission of infectious diseases. Vaccines can contain live attenuated, killed organisms or newer technologies such as mRNA, that stimulates the human body to develop anti-bodies against the organism. Vaccines or any medication go through several stages of trials (clinical trials), in which the efficacy and safety are evaluated through scientific methods.
Ever since COVID-19 was declared a worldwide pandemic, countries have been racing to develop vaccines to help in stopping the transmission of the disease. Currently, there are number of vaccines that have proven to be effective and safe through clinical trials.
Approved vaccines in Saudi Arabia
BNT162b2 is mRNA type of vaccine and one of the available vaccines that are proven effective against SARS-CoV-2. The vaccine went through the 3 phase clinical trial where close to 44 thousands participants were recruited, around 18 thousands in each arm. The vaccine showed around 95% in preventing COVID-19 in intervention arm. mRNA vaccines are a new type of vaccine to protect against infectious diseases. To trigger an immune response, they teach our cells how to make a protein—or even just a piece of a protein—that triggers an immune response inside our bodies. That immune response, which produces antibodies, is what protects us from getting infected if the real virus enters our bodies.
In 11th of December the FDA approved the vaccine for emergency use authorization (EUA) in individual older than 16 years of age. The SFDA approved the vaccine as well to be used in the kingdom of Saudi Arabia.
AZD1222 is a product of collaboration between Oxford University and pharmaceutical company AstraZeneca, the vaccine is reported to have an efficacy of 63% according to clinical trials. According to the literature the vaccine is intended to be used in age group of 18 years and older.
It deploys a replication-deficient chimpanzee viral vector based on a weakened version of a common cold virus (adenovirus) that causes infections in chimpanzees. It contains the genetic materials of the spike protein. After vaccination, the cells produce the spike protein, stimulating the immune system to attack the SARS-CoV-2 virus.
||Pfizer-BioNTech – (BNT162b2)
- The vaccine is administered through intramuscular route in 2-dose series, 0.3 ml each.
- The second dose should be administered within the range of 19-23 days after the first dose has been administered.
- If there’s any delay between the doses, the second dose should be administered as soon as possible (within 30 days) without recitation of doses.
- Studies shown that the level of efficacy following the. First dose is only 52%.
- BNT162b2 should be administered alone and spaced carefully, 14 days prior and 14 days after of any administration of any type of vaccine.
- If administered within that range, no doses shouldn’t be repeated.
- The vaccine is administered through intramuscular (Deltoid) route in 2-dose series, 0.5 ml each.
- Duration between doses should be between 8-12 weeks. If the second dose is administered less than 4 weeks after the first, the dose does not need to be repeated.
- If administration of the second dose is inadvertently delayed beyond 12 weeks, it should be given at the earliest possible opportunity. It is recommended that all vaccinated individuals receive two doses.
- There should be a minimum interval of 14 days between administration of this vaccine and any other vaccine against other conditions.
- There is currently no evidence indicating a need for further doses once an individual has received two doses.
- No data are available on the interchangeability of doses of this vaccine with other COVID-19 vaccines. It is currently recommended that the same product should be used for both doses
||Prior history of COVID-19 infection or Exposure:
- Based on the observed reinfection of COVID-19, subject are unlikely to get re-infected with COVID-19. Patients who are infected with COVID-19 or had recent COVID-19 infection should delay their vaccination until 90 days have passed since their infection.
- Subjects who had recent exposure to confirmed cases shouldn’t be vaccinated until the quarantine period is over.
Persons with current acute COVID-19:
- Persons with acute PCR-confirmed COVID-19, including those with onset of PCR-confirmed infection between doses, should not be vaccinated until after they have recovered from acute illness and the criteria for discontinuation of isolation have been met
Subjects who received plasma therapy during their infection:
- They should delay their vaccination until 90 days have passed to ensure there isn’t an interference from antibodies received by plasma and vaccine response.
- Subjects who are known to have an allergy against any of the vaccine component should not be vaccinated until further evidence is available.
- Subjects who have history of anaphylaxis following any type of vaccination or intramuscular injections should not be vaccinated until further evidence is available.
- Subjects who experience anaphylaxis shock following first dose of vaccine should not receive second dose.
- Providers should monitor the receiver for a period of 10-30 mins for signs of anaphylactic reactions after administration.
- Anyone with an acute febrile illness (body temperature over 38.5) should postpone vaccination until afebrile.
- The presence of minor infection, such as a cold, or low-grade fever should not delay vaccination.
- To this date, data is not available about the safety of the vaccine in immunocompromised patients (HIV, patients on immunosuppressant drugs and immunocompromising diseases).
- Risk and benefit should be evaluated by the treating physician and the discussion with the patient about the available data on safety before administration of the vaccine.
- They should be educated about the type of the vaccine and that It doesn’t contain live virus or attenuated.
- They should understand that the efficacy in their condition is still to be evaluated and may differ from typical response. They should follow precautions after vaccination.
Persons with autoimmune conditions:
- No available data on safety of the vaccine. However, people with autoimmune disease should be considered.
Pregnancy and breast feeding:
- To this date, data is not available about the safety of the vaccine in pregnant women, though the vaccine is not live vaccine.
- Pregnant women or those planning to conceive in the near future, can receive the vaccine as they are more prone to sever form of the disease, and should be educated about the limited data available on safety.
- It’s not believed that the vaccine can adversely affect breastfeeding, and women who are at risk of infection should be vaccinated because of the higher benefits to harm ratio.
Anticoagulation therapy and bleeding disorders:
- Prior to vaccination, subjects on anticoagulant therapy or who have bleeding disorder should counsel their treating physician regarding the safety of injection.
- Patients who are on warfarin can be vaccinated via intramuscular route if they are up to date with their INR testing and are below the upper level of therapeutic range. Vaccine can be taken as well in patients on Direct Oral Anticoagulants if they are stable.
- Following the administration of injection, health care provider should monitor the injection site for any bleeding and educate the subject about the risk of hematoma from the injection.
- During counseling, it’s important to emphasize on the importance of continuing to adhere to universal masking, hand hygiene and social distancing, especially between the doses.
- Educate the receiving subject about the possible side effect that are common to the vaccine such as (pain, swelling at the site of the injection, fever, fatigue, and myalgia) and to report to health care facility if any other side effects out of the norm appears.
*Disclaimer: This guideline is updated according to the latest available data and evidence.