There is no obligation in Cape Verde to have carried out certain vaccines as it may be the case in other countries of the continent.
However, be sure to have your vaccines up to date to travel.
Here, in case of health problem, do not expect a European management.
All islands have hospital structures, more or less well equipped depending on the case. In Santo Antão, the main hospital is in Ribeira Grande. This establishment is not equipped to take care of serious pathologies. If this happens, you will have to be transferred to Mindelo to be hospitalized in the public hospital, where in one of the private structures of the island. (For information, the transfer of the wounded is done ... by boat.)
In addition to the Ribeira Grande Hospital, there are clinics and health centers all over the island that are able to cope with emergencies while awaiting evacuation.
Rescue & Evacuation
On Santo Antão, assume that you will have to rely on yourself.
In the event of an accident in the mountains, it is necessary to succeed to join the nearest road to evacuate the victim on a hospital center. The locals will come to help you, it is not refusal.
Evacuation in ambulance? Not really, it will probably be an "Aluguer" that will take you.
Do not hesitate to tell the driver to lift his foot if the driving is not adapted to the condition of the victim.
Lucky as we are, we do not have that kind of stuff here.
On Santo Antão, there are relatively few mosquitoes, which does not prevent you from being careful, especially in the summer.
On the other hand, they are present on other islands of the archipelago, with, among other things, the appearance of the Zika virus.
Water & Food
The water of Santo Antão is reputed to be good, but we advise you to privilege the water in bottles to hydrate you. There is no particular risk in using mains water to wash your teeth, or to prepare your meals.
Otherwise, it will be necessary to privilege the Strela, local beer ...
As for your diet, do not miss the fruits, vegetables and cheeses from here. But never forget that it is imperative to wash them well.
Depending on where you eat, the rules of hygiene vary. If in doubt, do not take any chances.