Hi,Thanks for selecting our forum. The vaccine you had mentioned about is pneumococcal conjugate vaccine(PCV). It is a compulsory vaccine in most of the countries. In certain developing countries,it is an optional vaccine. It is a preventive measure against pneumococcus bacteria which commonly produces pneumonia. Yes,it is a costly vaccine but it is cost-effective. But madam, if you are really going compromise the minimum 3 shots for financial reasons, i would suggest you to atleast take one more shot to have a small boosted immunity of the earlier shot. This is just to give a balance between your finance and your child's health and nothing else. Regards,Dr.Pravin Asir.