Flu vaccines are vaccines that protect against influenza. Every year new version of vaccines are developed as the flu virus changes rapidly. The effectiveness varies from year to year providing medium to high protection. Flu vaccines are not that much effective for children under 2 years and adult of above 65 years.
Flu shots are generally safe. Only around 5 to 10% of the children who are vaccinated suffer from fever. Flu vaccines come in both active and inactive forms. Inactive flu shots are used for pregnant women. For them, the shot is injected into the muscle, sprayed in the nose, or given in to the skin. The vaccine even minimizes the spread of flu. It is even prominent to reduce the severity of the flu if an individual contract a flu strain that the vaccine did not contain. The vaccine shows its maximum effect after2 weeks.
Flu Vaccine Manufacture
Influenza vaccine is manufactured using three prime technologies. Most of the flu vaccine manufacturers are private manufacturers. They are explained below:
Egg-Based Flu Vaccines:
It is an egg-based manufacturing process making inactivated vaccine called the flu shot and live attenuated vaccine called the nasal spray. The manufacturer starts the production process with CDC or another laboratory partner in the WHO. The WHO global surveillance system provides the private manufacturers with candidate vaccine viruses (CVVs) grown in eggs as per current FDA regulatory requirements.
The prepared CVVs are fertilized in eggs to replicate the virus. For the shots, the virus is inactive and the antigen is purified. For the attenuated nasal spray vaccine, the CVVs follow a different production process. This manufacturing process takes longer time as it requires lots of chicken eggs.
Cell-Based Flu Vaccines:
It produces cell grown CVVs. In this manufacturing process, first, the WHO distributes the cell-grown CVVs to manufacturers. In the second step, the manufacturers inoculate the CVVs into cultured mammalian cells and allow for their replication. At last, after the replication is complete the virus containing fluid is collected and the virus antigen is purified. Before marketing the vaccine FDA tests and approvals are a must.
Recombinant Flu Vaccines:
It is the newest vaccine technology utilizing recombinant technology. For the manufacture of vaccine by recombinant DNA, a protein is isolated from a wild type recommended vaccine virus. The protein that is isolated is HA protein as it induces an immune response in people. Next, the isolated proteins are combined with portions of another virus that grows good enough in insect cells.
The mixture produces a “recombinant” vaccine which is further mixed with insect cells and allowed to replicate. The flu HA protein purified from these cells.The purified protein is given FDA testing and approval.
List of flu vaccine manufacturers
The companies that have produced inactivated and attenuated flu vaccines are as follows:
- Glaxosmith Kline
- Sanofi Pasteur
- Protein Sciences