If you are unsure about taking the COVID-19 vaccine, or have questions about how one vaccine differs from the other, why you need to take two doses and what happens if you skip the second dose, the Oxford Astra Zanka has answers.
These are the responses to commonly asked questions on the COVID-19 vaccine as shared by those companies.
Why do I need to take two doses of COVID-19 vaccine?
The vaccine activates two types of cells, but they are short-lived. Active cells for a short time will not give you adequate protection. Adhere to the second dose to receive better results.
Can I skip the second dose of the COVID-19 vaccine?
The second dose is a tool to expose the body again to antigens (molecules) that exist in the disease and trigger an immune response.
How vaccines offer an effective solution to a pandemic.
A vaccine prepares the body to fight the infection caused by viruses or bacteria. The vaccine contains inactivated or weakened particles of the virus that causes the disease, or contains the genetic code that works to provoke an immune response. This helps the body recognise foreign invaders and produce antibodies to fight them.
The second dose of any vaccine has incomparable effectiveness with the first. Although your body might build antibodies after the first dose, without the second shot this is often followed by a rapid decline.
On receiving the second dose, antibodies appear again in the body in large numbers.
What is herd immunity and how is it achieved?
Herd immunity is a form of indirect protection from an infectious disease. With herd immunity, the spread of the disease from person to person becomes unlikely.
Herd immunity occurs when a sufficient percentage of the population has become immune to an infection, whether through vaccination or previous infections.
Some important information about the differences between COVID-19 vaccines.
There are various differences among vaccines, according to manufacturing and saving features. Despite that, all vaccines work to provoke an immune response and produce antibodies to fight the virus in case of infection.
What is the Oxford-AstraZeneca vaccine?
Research has shown it is highly effective. No one given the vaccine in trials developed severe Covid or needed hospital treatment. Unlike Pfizer’s jab – which has to be kept at an extremely cold temperature (-70C) – the Oxford vaccine can be stored in a normal fridge. This makes it much easier to distribute.
The University of Oxford partnered with the British-Swedish company AstraZeneca to develop and test a coronavirus vaccine known as ChAdOx1 nCoV-19 or AZD1222. Clinical trials found that the vaccine had an efficacy of 82.4 percent when two doses were given 12 weeks apart. Despite some uncertainty over trial results, Britain authorized the vaccine for emergency use in December, and India authorized a version of the vaccine called Covishield on Jan.
How does the Serum-Oxford vaccine work?
The Oxford-AstraZeneca vaccine is based on the virus’s genetic instructions for building the spike protein. But unlike the Pfizer-BioNTech and Moderna vaccines, which store the instructions in single-stranded RNA, the Oxford vaccine uses double-stranded DNA.
The researchers added the gene for the coronavirus spike protein to another virus called an adenovirus. Adenoviruses are common viruses that typically cause colds or flu-like symptoms. The Oxford-AstraZeneca team used a modified version of a chimpanzee adenovirus, known as ChAdOx1. It can enter cells, but it can’t replicate inside them.
The Oxford-AstraZeneca vaccine for Covid-19 is more rugged than the mRNA vaccines from Pfizer and Moderna. DNA is not as fragile as RNA, and the adenovirus’s tough protein coat helps protect the genetic material inside. As a result, the Oxford vaccine doesn’t have to stay frozen. The vaccine is expected to last for at least six months when refrigerated at 38–46°F (2–8°C).
The level of antibodies may decline over months but the immune system contains cells that are called memory cells. These cells could save information about coronavirus for years. The cells can remember the disease in case of exposure, and trigger the immune system to produce antibodies to fight the virus.
Scientist also discovered that the memory cells had gone through numerous rounds of mutation even after the infection was resolved. As a result, the antibodies they produced were much more effective than the originals. Extra laboratory experiments have also shown that these antibodies are able to recognise the mutated strains of the virus, like the one in South Africa. Studies proved that vaccines differ in their effectiveness levels with the South African strain, but are still effective despite the differences. Therefore, it is important to take the vaccine and abide by the second dose.