Members should be assured that vaccines DO protect against a huge number of infectious diseases at all ages, whether at home or travelling. If only there were vaccines available to everyone who needed them, and for all infections ! Were still waiting for AIDS, malaria, and dengue vaccines, but many other safe and effective vaccines exist.
Active immunity can be acquired by natural disease or vaccines. Vaccines stimulate the immune system and consist of
Live, attenuated ( weakened ) forms of viruses ( measles, mumps, rubella ) or bacteria ( BCG )
Inactivated viruses ( flu ) or bacteria
Weakened toxins produced by the bug ( tetanus )
Extracts of the bug ( pneumococcal ) or from recombinant DNA ( hepatitis B ).
Most bugs are antigenically stable , for immunisation purposes. ( Antibiotic resistance is another matter ). Influenza viruses A and B are constantly changing, as shown by the H and N antigens on their surfaces. Thats why the flu vaccine is needed every year for at risk people wherever they live. World Health Organisation ( WHO ) identifies in advance the viruses most likely to cause flu and vaccines are made to match them. This year the three flu viruses are H1N1 ( swine flu ), H3N2 and B/Wisconsin/1.
By all means compare my detailed information about BCG on the forum (
http://filipinaroses.com/showthread....long-way-to-go ) with other sites. At the end of the day Im only giving an informed opinion but I take time and care to make sure the information is accurate to the best of my knowledge ! Note the forum disclaimer " Anything posted in this section is the poster's own opinion and may not be accurate. Please seek professional advice. " Members can decide for themselves whether or not I and my posts are professional.